Set fx.StopTimeout inside the container stop grace (closes #134)

fx defaults the stop timeout to 15s and the Dockerfile sets no
STOPSIGNAL or grace override, so Docker's 10s default SIGKILLs the
process five seconds before the bound can fire. Everything gated on
it — including the "shutdown timed out, goroutines still running"
error log that tells an operator a component is wedged — was
unreachable in the image this repo produces.

Set fx.StopTimeout to 5s: inside the grace with headroom for signal
delivery and process exit. The option set moves into newApp() so a
test can read (*fx.App).StopTimeout() back and pin it against
drift; dropping the option makes that test report fx's 15s default.

Lower the HTTP drain budget (server.ShutdownTimeout) from 5s to 3s.
fx bounds the whole stop sequence and returns without running its
remaining hooks once the stop context expires, so two equal values
meant a drain that used its full budget exhausted the sequence
budget at that instant and skipped every later hook — the delivery
engine, the healthcheck, the webhook DB manager and the database
close — in exactly the case where the drain mattered. The tail
hooks are microsecond-scale in normal operation, so 2s of remaining
budget is ample, and holding the total at 5s keeps a wide margin
under Docker's 10s grace. The constant is exported so
TestStopTimeout_LeavesHeadroomForTailHooks can pin the relationship
and fail on a future edit to either value. This does not make the
database close unconditional: the ArchiveSweeper and RetentionReaper
hooks run before the server and can still consume the whole budget.

Also fix a latent coin flip in the shared stop-hook waiter. It
selected on the drained channel against ctx.Done() with no
preamble, and select picks uniformly among ready cases, so a
component that drained against an already-expired context reported
a timeout about half the time. Not reachable through fx, which
re-checks ctx.Err() before each hook, but the helper is shared and
a direct caller can reach it. waitDone now settles the drained case
in a non-blocking preamble first; the test drives it over 1000
passes, so a restored coin flip cannot pass by luck.

README records the real stop-hook order (ArchiveSweeper,
RetentionReaper, server, delivery.Engine, healthcheck,
WebhookDBManager, database close), the two timeouts and their
relationship, and the container stop grace: that lowering the grace
below the bound puts SIGKILL back in front of it, and that an
expired stop context makes fx skip its remaining hooks, so a wedge
in the first-stopped component means the database close never runs.
Adds the missing internal/lifecycle/ entry to the Package Layout
tree.

.dockerignore

@@ -3,6 +3,11 @@
 # stage of the Dockerfile.
 .git/
 bin/
+# Third-party browser assets are fetched and hash-verified inside the build by
+# script/fetch-assets. Excluding any host copy keeps a developer's working tree
+# from supplying the bytes that get shipped. The script and its
+# static/vendor.sha256 manifest stay in the context.
+static/js/alpine.min.js
 *.md
 LICENSE
 .editorconfig

.gitignore

@@ -44,4 +44,9 @@ tmp/
 temp/
 
 # CI cache barrier, written into the build context by the check workflow
-.ci-fingerprint 
+.ci-fingerprint
+
+# Third-party browser assets, fetched and hash-verified by
+# script/fetch-assets against static/vendor.sha256. Not committed:
+# REPO_POLICIES.md forbids minified bundles in version control.
+/static/js/alpine.min.js 

Dockerfile

@@ -32,7 +32,7 @@ FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a349228
 # Depend on lint stage passing
 COPY --from=lint /src/go.sum /dev/null
 
-RUN apt-get update && apt-get install -y --no-install-recommends make && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /build
 
@@ -44,6 +44,14 @@ RUN go mod download
 # the lint stage above.
 COPY . .
 
+# Fetch the third-party browser assets the UI serves. They are not committed
+# (REPO_POLICIES.md forbids minified bundles in version control) and
+# .dockerignore keeps any host copy out of the build context, so this step is
+# the only way they enter the image. Each download is checked against a
+# hardcoded sha256 and the build fails on mismatch; make test re-checks the
+# hashes against the bytes go:embed actually put in the binary.
+RUN script/fetch-assets
+
 # Run tests and build
 RUN make test
 RUN make build

Makefile

@@ -1,4 +1,4 @@
-.PHONY: bootstrap setup test lint fmt fmt-check check build run dev deps docker clean hooks css
+.PHONY: bootstrap setup assets test lint fmt fmt-check check build run dev deps docker clean hooks css
 
 # Default target
 .DEFAULT_GOAL := check
@@ -9,6 +9,9 @@ bootstrap:
 setup:
 	@script/setup
 
+assets:
+	@script/fetch-assets
+
 test:
 	@script/test
 

README.md

@@ -40,6 +40,7 @@ make docker
 ```bash
 make bootstrap  # Install all dependencies (idempotent)
 make setup      # Bootstrap + install git pre-commit hook
+make assets     # Fetch + verify third-party browser assets
 make fmt        # Format code (gofmt + goimports)
 make lint       # Run golangci-lint
 make test       # Run tests with race detection
@@ -247,6 +248,8 @@ them. We provide:
 - `script/setup` — make a fresh clone ready for development
   (bootstrap, then install-precommit)
 - `script/projectname` — output the project name ("webhooker")
+- `script/fetch-assets` — download the third-party browser assets into
+  `static/`, verifying each against its pinned sha256
 - `script/test` — run the test suite
 - `script/lint` — run golangci-lint
 - `script/fmt` — format all code (writes)
@@ -260,6 +263,27 @@ them. We provide:
 - `script/install-precommit` — install the git pre-commit hook that
   runs `script/precommit`
 
+## Third-party browser assets
+
+The web UI serves one third-party script, Alpine.js. It is **not** committed:
+a minified bundle in the tree is unreviewable, and `REPO_POLICIES.md` bars
+both committed build artifacts and unpinned external references.
+
+Instead `script/fetch-assets` downloads it from a pinned URL, checks the
+download against a hardcoded sha256, and installs it under `static/`. The
+sha256 of every installed asset is recorded in `static/vendor.sha256`, and
+`static/vendor_test.go` re-hashes the bytes `go:embed` put in the binary
+against that manifest — so the pin is enforced on what actually ships, not
+merely written down. Any mismatch fails the build.
+
+`make bootstrap` runs the fetch for local development, and the Dockerfile
+runs it in the build stage; `.gitignore` and `.dockerignore` keep the
+artifact out of both the repo and the build context.
+
+To move to a new version: update the version, URL, and tarball sha256 in
+`script/fetch-assets` and the asset sha256 in `static/vendor.sha256`, then
+run `make assets && make check`.
+
 ## Rationale
 
 Webhook integrations between services are inherently fragile. The
@@ -1040,6 +1064,8 @@ webhooker/
 │   │   └── webhook.go         # Webhook receiver handler
 │   ├── healthcheck/
 │   │   └── healthcheck.go     # Health check service (uptime, version)
+│   ├── lifecycle/
+│   │   └── lifecycle.go       # Shared stop-hook waiter, bounded by the stop context
 │   ├── logger/
 │   │   └── logger.go          # slog setup with TTY detection
 │   ├── middleware/
@@ -1165,6 +1191,64 @@ downstream at form-parse time.
 - Container runs as non-root user (UID 1000)
 - GORM soft deletes on all entities (data preserved for audit)
 
+### Shutdown
+
+On SIGINT or SIGTERM, fx runs the registered stop hooks in reverse
+dependency order under a **5 second budget** (`fx.StopTimeout` in
+`cmd/webhooker/main.go`). That budget covers the whole sequence, not
+each hook. The order, read off the fx stop-hook log:
+
+1. `ArchiveSweeper`
+2. `RetentionReaper`
+3. `server` — the HTTP drain, bounded separately by
+   `server.ShutdownTimeout` (**3 seconds**)
+4. `delivery.Engine`
+5. `healthcheck`
+6. `WebhookDBManager`
+7. the database close
+
+The two components that can realistically hold the budget run
+first: a retention sweep or an archive prune caught mid-tick each
+waits on its `WaitGroup` bounded by the stop context, so a wedge
+there consumes the 5 seconds before the HTTP server hook is ever
+entered. The hooks after the server are microsecond-scale in normal
+operation.
+
+The HTTP drain budget is deliberately **shorter** than the sequence
+budget. Were the two equal, a drain that used its whole budget would
+exhaust the sequence budget at the instant it finished, and every
+later hook — the delivery engine, the healthcheck, the webhook DB
+manager and the database close — would be skipped in exactly the
+case where the drain mattered. 3 seconds leaves 2 seconds for the
+tail, which is far more than it needs. This does not make the
+database close unconditional: a wedged `ArchiveSweeper` or
+`RetentionReaper` still runs first and can consume the whole budget
+on its own.
+
+The value is chosen to sit inside the container stop grace period.
+Docker's default `docker stop` grace is 10 seconds and the Dockerfile
+sets no `STOPSIGNAL` or grace override, so the process must be gone
+before that. fx's own default is 15 seconds, which is past the grace:
+the container would be SIGKILLed (exit 137) before the bound could
+fire, and nothing that depends on it — including the
+`shutdown timed out, goroutines still running` error log that tells
+an operator a component is wedged — would ever be reached.
+
+Two operational consequences follow from bounding the sequence:
+
+- **A wedged component aborts the rest of the shutdown.** fx checks
+  the stop context before each remaining hook and returns outright
+  once it has expired, skipping the hooks it has not reached. If the
+  first-stopped component consumes the whole budget, the later hooks
+  never run — **the database close among them**. SQLite is crash-safe,
+  so this is not corruption, but it is not a clean close either.
+- **Lowering the grace below 5 seconds reintroduces the silent
+  truncation.** `docker stop --time`, Compose's `stop_grace_period`,
+  or Kubernetes' `terminationGracePeriodSeconds` set under 5 seconds
+  put SIGKILL back in front of the bound, and the process dies with
+  no shutdown diagnostics at all. Keep the deployment's grace above
+  the stop timeout.
+
 ### Docker
 
 The Dockerfile uses a multi-stage build:

cmd/webhooker/main.go

@@ -2,6 +2,8 @@
 package main
 
 import (
+	"time"
+
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/database"
@@ -15,6 +17,29 @@ import (
 	"sneak.berlin/go/webhooker/internal/session"
 )
 
+// stopTimeout bounds the whole fx stop sequence, not each hook.
+//
+// fx defaults to 15s, which is longer than Docker's 10s default
+// stop grace: the container would be SIGKILLed before the bound
+// could fire, so nothing bounded by it would ever be observed.
+// 5s leaves headroom inside that grace for signal delivery and
+// process exit; the observed wedge case already exits at ~5.3s,
+// so a larger bound would trade a rare skipped database close for
+// a more common hard kill.
+//
+// It must stay strictly above server.ShutdownTimeout: an HTTP
+// drain that uses its whole budget would otherwise exhaust the
+// sequence budget at that instant, and fx would skip every hook
+// after the server — the delivery engine, the healthcheck, the
+// webhook DB manager and the database close. Those tail hooks are
+// microsecond-scale in normal operation, so the 2s difference is
+// ample. TestStopTimeout_LeavesHeadroomForTailHooks pins it.
+//
+// This does not make the database close unconditional: the
+// ArchiveSweeper and RetentionReaper hooks run before the server
+// and can still consume the whole budget on their own.
+const stopTimeout = 5 * time.Second
+
 // Build-time variables set via -ldflags.
 //
 //nolint:gochecknoglobals // Build-time variables injected by the linker.
@@ -27,7 +52,14 @@ func main() {
 	globals.Appname = appname
 	globals.Version = version
 
-	fx.New(
+	newApp().Run()
+}
+
+// newApp builds the application graph. It is separate from main so
+// a test can assert the options it carries.
+func newApp() *fx.App {
+	return fx.New(
+		fx.StopTimeout(stopTimeout),
 		fx.Provide(
 			globals.New,
 			logger.New,
@@ -60,5 +92,5 @@ func main() {
 			) {
 			},
 		),
-	).Run()
+	)
 }

cmd/webhooker/main_test.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/server"
+)
+
+// dockerStopGrace is Docker's default `docker stop` grace period.
+// The Dockerfile sets no STOPSIGNAL or grace override, so this is
+// the deadline the container is actually held to, and the fx stop
+// timeout has to fit inside it with room for signal delivery and
+// process exit.
+const dockerStopGrace = 10 * time.Second
+
+// TestNewApp_StopTimeout pins the fx stop timeout. Without the
+// explicit fx.StopTimeout option the app reads fx's 15s
+// DefaultTimeout, which exceeds dockerStopGrace: the container is
+// SIGKILLed before the bound fires and every shutdown hook bounded
+// by it — including the operator-facing timeout log — becomes
+// unreachable in the image this repo produces.
+//
+// fx.New applies options before it executes invokes, so the timeout
+// is set whether or not the graph itself can be constructed here.
+func TestNewApp_StopTimeout(t *testing.T) {
+	t.Setenv("DATA_DIR", t.TempDir())
+
+	got := newApp().StopTimeout()
+
+	require.Equal(t, stopTimeout, got)
+	require.Less(t, got, dockerStopGrace)
+}
+
+// tailHeadroom is the slack the fx stop budget must keep beyond the
+// HTTP drain. The hooks that run after the server — the delivery
+// engine, the healthcheck, the webhook DB manager and the database
+// close — are microsecond-scale in normal operation, so this is
+// generous for them.
+const tailHeadroom = 2 * time.Second
+
+// TestStopTimeout_LeavesHeadroomForTailHooks pins the relationship
+// between the HTTP drain budget and the fx stop budget. fx bounds
+// the whole stop sequence, and returns without running its
+// remaining hooks once the stop context has expired. If the two
+// values were equal, an HTTP drain that used its full budget would
+// exhaust the sequence budget at the instant it finished and every
+// later hook, the database close included, would be skipped in
+// exactly the case where the drain mattered.
+//
+// Lowering either constant to erase the gap must fail here rather
+// than silently recreating that.
+func TestStopTimeout_LeavesHeadroomForTailHooks(t *testing.T) {
+	t.Parallel()
+
+	require.Less(t, server.ShutdownTimeout, stopTimeout)
+	require.GreaterOrEqual(
+		t, stopTimeout-server.ShutdownTimeout, tailHeadroom,
+	)
+}

internal/delivery/target_config_view.go

@@ -106,6 +106,12 @@ func slackConfigFields(configJSON string) []ConfigField {
 // and its retry settings. Header values are not shown — they
 // routinely carry authorization tokens — only how many are
 // configured.
+//
+// The destination is masked to scheme and host by the same
+// rule the Slack target uses. An HTTP target's destination is
+// commonly a Slack, Discord or Teams incoming-webhook endpoint
+// whose path segments are the credential, and the field takes
+// an arbitrary URL, so no segment can be assumed non-secret.
 func httpConfigFields(t *database.Target) []ConfigField {
 	cfg, err := parseHTTPConfig(t.Config)
 	if err != nil {
@@ -114,7 +120,7 @@ func httpConfigFields(t *database.Target) []ConfigField {
 
 	fields := []ConfigField{{
 		Label: "Destination URL",
-		Value: cfg.URL,
+		Value: MaskURL(cfg.URL),
 	}}
 
 	if cfg.Timeout > 0 {

internal/delivery/target_config_view_test.go

@@ -19,6 +19,7 @@ const (
 
 	viewExampleOrigin = "https://example.com"
 	viewExampleHook   = viewExampleOrigin + "/hook"
+	viewMaskedOrigin  = viewExampleOrigin + "/..."
 	viewUnavailable   = "(unavailable)"
 	viewExpiryNever   = "never"
 )
@@ -162,7 +163,7 @@ func TestNewTargetViews_HTTP(t *testing.T) {
 	assert.Equal(
 		t,
 		map[string]string{
-			"Destination URL": viewExampleHook,
+			"Destination URL": viewMaskedOrigin,
 			"Timeout":         "30s",
 			"Headers":         "1 configured",
 			"Max Retries":     "5",
@@ -188,13 +189,41 @@ func TestNewTargetViews_HTTPFireAndForget(t *testing.T) {
 	assert.Equal(
 		t,
 		map[string]string{
-			"Destination URL": viewExampleHook,
+			"Destination URL": viewMaskedOrigin,
 			"Max Retries":     "0 (fire-and-forget)",
 		},
 		fieldMap(view.Config),
 	)
 }
 
+// TestNewTargetViews_HTTPMasksDestinationURL proves the rule
+// holds for the http target too: an http destination is
+// routinely an incoming-webhook endpoint whose path segments
+// are the credential, so none of them is shown.
+func TestNewTargetViews_HTTPMasksDestinationURL(t *testing.T) {
+	t.Parallel()
+
+	view := viewFor(t, database.Target{
+		Type:   database.TargetTypeHTTP,
+		Config: `{"url":"` + slackWebhookURL + `"}`,
+	})
+
+	fields := fieldMap(view.Config)
+
+	assert.Equal(
+		t,
+		"https://hooks.slack.com/...",
+		fields["Destination URL"],
+	)
+
+	for _, v := range fields {
+		assert.NotContains(t, v, slackSecretPath)
+		assert.NotContains(t, v, "T00000000")
+		assert.NotContains(t, v, "B00000000")
+		assert.NotContains(t, v, "XXXXXXXXXXXXXXXXXXXXXXXX")
+	}
+}
+
 func TestNewTargetViews_Database(t *testing.T) {
 	t.Parallel()
 

internal/handlers/event_log_view.go

@@ -0,0 +1,120 @@
+package handlers
+
+import (
+	"time"
+	"unicode/utf8"
+)
+
+// maxRenderedBodyBytes caps how many bytes of a stored event
+// body reach the event log page. Bodies come from the
+// unauthenticated receiver under the 1 MB ingest cap and
+// renderTemplate buffers a whole page before writing it, so
+// an uncapped page of paginationPerPage events is tens of
+// megabytes of resident memory per concurrent viewer.
+const maxRenderedBodyBytes = 8192
+
+// eventLogColumns is the event log's projection. The casts to
+// blob are load-bearing: they make substr and length count
+// bytes rather than characters, so the cap bounds the page in
+// bytes whatever the payload's encoding. Cutting in SQLite
+// rather than in Go is the point of the projection — an
+// oversized body never becomes a Go string at all.
+const eventLogColumns = "id, created_at, method, content_type, " +
+	"substr(cast(body as blob), 1, ?) AS body, " +
+	"length(cast(body as blob)) AS body_bytes"
+
+// EventLogView is the display-safe projection of an event for
+// the event log page, alongside DeliveryView and TargetView.
+// It carries a capped body plus the true stored size, so the
+// page can mark a body as truncated without ever holding the
+// whole thing.
+type EventLogView struct {
+	ID          string
+	CreatedAt   time.Time
+	Method      string
+	ContentType string
+
+	// Body holds at most maxRenderedBodyBytes bytes of the
+	// stored body.
+	Body string
+
+	// BodyBytes is the true size of the stored body.
+	BodyBytes int64
+
+	// BodyTruncated reports that the stored body was larger
+	// than the cap, so the page owes the reader a marker.
+	BodyTruncated bool
+
+	Deliveries []DeliveryView
+}
+
+// BodyShownBytes is how many body bytes the page is actually
+// rendering, which the truncation marker reports beside the
+// true size.
+func (v EventLogView) BodyShownBytes() int {
+	return len(v.Body)
+}
+
+// eventLogRow is one row of the event log projection. Its
+// body column arrives already cut to the cap by SQLite, with
+// the true size beside it.
+type eventLogRow struct {
+	ID          string
+	CreatedAt   time.Time
+	Method      string
+	ContentType string
+	Body        []byte
+	BodyBytes   int64
+}
+
+// view projects a loaded row for rendering.
+func (r *eventLogRow) view() EventLogView {
+	body := r.Body
+	truncated := r.BodyBytes > int64(len(body))
+
+	// Only a cut body can have been left mid-sequence by
+	// this query. A whole body is passed through exactly as
+	// stored, however malformed.
+	if truncated {
+		body = trimPartialRune(body)
+	}
+
+	return EventLogView{
+		ID:            r.ID,
+		CreatedAt:     r.CreatedAt,
+		Method:        r.Method,
+		ContentType:   r.ContentType,
+		Body:          string(body),
+		BodyBytes:     r.BodyBytes,
+		BodyTruncated: truncated,
+	}
+}
+
+// trimPartialRune drops a trailing UTF-8 sequence that the
+// byte-wise cut left incomplete, so a multi-byte rune severed
+// at the cap does not surface as a mojibake tail.
+//
+// Bytes that are merely invalid UTF-8 are left exactly as
+// stored: this service receives binary payloads, and rewriting
+// them would misreport what was delivered. The distinction is
+// utf8.FullRune's — it reports a complete sequence for an
+// invalid encoding too, since that decodes to a width-1 error
+// rune, so only a valid prefix still waiting for its
+// continuation bytes is removed. A tail with no rune start in
+// its last utf8.UTFMax bytes cannot be an incomplete sequence
+// either, and is likewise left alone.
+func trimPartialRune(b []byte) []byte {
+	for i := len(b) - 1; i >= 0 && len(b)-i <= utf8.UTFMax; i-- {
+		if !utf8.RuneStart(b[i]) {
+			continue
+		}
+
+		if utf8.FullRune(b[i:]) {
+			return b
+		}
+
+		return b[:i]
+	}
+
+	return b
+}

internal/handlers/event_log_view_test.go

@@ -0,0 +1,258 @@
+package handlers_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"testing"
+	"unicode/utf8"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+	"sneak.berlin/go/webhooker/internal/handlers"
+	"sneak.berlin/go/webhooker/internal/session"
+)
+
+// bodyCap is the number of body bytes the event log page is
+// allowed to render for one event.
+const bodyCap = handlers.MaxRenderedBodyBytesForTest
+
+// snowman is a three-byte rune, so a body of them straddles the
+// byte-wise cut: bodyCap is not a multiple of three.
+const snowman = "☃"
+
+// seedEventWithBody records one event with the given body in the
+// webhook's own database.
+func seedEventWithBody(
+	t *testing.T,
+	dbMgr *database.WebhookDBManager,
+	webhookID string,
+	body string,
+) {
+	t.Helper()
+
+	webhookDB, err := dbMgr.GetDB(webhookID)
+	require.NoError(t, err)
+
+	event := &database.Event{
+		WebhookID:   webhookID,
+		Method:      http.MethodPost,
+		Body:        body,
+		ContentType: "application/octet-stream",
+	}
+
+	require.NoError(t, webhookDB.Omit(
+		clause.Associations,
+	).Create(event).Error)
+}
+
+// seedAndProject stores one body and returns the projection the
+// event log page would be handed for it.
+func seedAndProject(
+	t *testing.T,
+	body string,
+) handlers.EventLogView {
+	t.Helper()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedEventWithBody(t, dbMgr, wh.ID, body)
+
+	views := h.LoadEventLogViewsForTest(
+		httptest.NewRecorder(), *wh, 1,
+	)
+	require.Len(t, views, 1)
+
+	return views[0]
+}
+
+// TestHandleSourceLogs_BoundsOversizeBody proves the rendered
+// page is bounded by the cap rather than by the stored payload:
+// the body here is 64 times the cap, and the ingest path would
+// accept twice as much again.
+func TestHandleSourceLogs_BoundsOversizeBody(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	const (
+		sentinel    = "TAIL-SENTINEL-1f4a9c"
+		storedBytes = 512 * 1024
+	)
+
+	wh := seedWebhook(t, db)
+	seedEventWithBody(
+		t, dbMgr, wh.ID,
+		strings.Repeat("A", storedBytes-len(sentinel))+sentinel,
+	)
+
+	page := renderSourceLogsPage(t, h, sess, wh.ID)
+
+	// Nothing past the cap reaches the page, and the whole page
+	// stays far below the stored body it is reporting on.
+	assert.NotContains(t, page, sentinel)
+	assert.Less(t, len(page), 4*bodyCap)
+
+	// The marker states the true stored size, not the cut one.
+	assert.Contains(
+		t, page,
+		"showing "+strconv.Itoa(bodyCap)+
+			" of "+strconv.Itoa(storedBytes)+" bytes",
+	)
+}
+
+// TestHandleSourceLogs_SmallBodyRendersWhole guards the other
+// side of the cap: a body under it is shown in full and carries
+// no truncation marker.
+func TestHandleSourceLogs_SmallBodyRendersWhole(t *testing.T) {
+	t.Parallel()
+
+	var (
+		h     *handlers.Handlers
+		sess  *session.Session
+		db    *database.Database
+		dbMgr *database.WebhookDBManager
+	)
+
+	app := newTestApp(t, &h, &sess, &db, &dbMgr)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedEventWithBody(t, dbMgr, wh.ID, `{"kept":"whole"}`)
+
+	page := renderSourceLogsPage(t, h, sess, wh.ID)
+
+	assert.Contains(t, page, ""kept"")
+	assert.NotContains(t, page, "Body truncated for display")
+}
+
+// TestEventLogView_CutMidRune proves a multi-byte rune severed
+// by the byte-wise cut is dropped rather than surfaced as a
+// mojibake tail.
+func TestEventLogView_CutMidRune(t *testing.T) {
+	t.Parallel()
+
+	body := strings.Repeat(snowman, 4096)
+	view := seedAndProject(t, body)
+
+	// bodyCap bytes hold bodyCap/3 whole snowmen and two bytes
+	// of the next one; those two are dropped.
+	whole := bodyCap / len(snowman)
+
+	assert.True(t, view.BodyTruncated)
+	assert.Equal(t, int64(len(body)), view.BodyBytes)
+	assert.Equal(t, strings.Repeat(snowman, whole), view.Body)
+	assert.True(t, utf8.ValidString(view.Body))
+	assert.LessOrEqual(t, len(view.Body), bodyCap)
+}
+
+// TestEventLogView_BinaryBodyLeftAsStored proves a binary
+// payload is passed through byte for byte. Its tail is invalid
+// UTF-8 however the cut falls, so repairing it would misreport
+// what the sender delivered.
+func TestEventLogView_BinaryBodyLeftAsStored(t *testing.T) {
+	t.Parallel()
+
+	raw := make([]byte, bodyCap+808)
+	for i := range raw {
+		// 0x80..0xBF: continuation bytes, never a rune start.
+		raw[i] = 0x80 | byte(i%0x40)
+	}
+
+	view := seedAndProject(t, string(raw))
+
+	assert.True(t, view.BodyTruncated)
+	assert.Equal(t, int64(len(raw)), view.BodyBytes)
+	assert.Equal(t, string(raw[:bodyCap]), view.Body)
+	assert.False(t, utf8.ValidString(view.Body))
+}
+
+// TestTrimPartialRune covers the distinction the cut repair
+// turns on: an incomplete but valid sequence is dropped, while
+// bytes that are merely invalid UTF-8 are left alone.
+func TestTrimPartialRune(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name string
+		in   []byte
+		want []byte
+	}{{
+		name: "complete ascii",
+		in:   []byte("abc"),
+		want: []byte("abc"),
+	}, {
+		name: "complete multibyte",
+		in:   []byte("ab" + snowman),
+		want: []byte("ab" + snowman),
+	}, {
+		name: "two byte rune cut",
+		in:   []byte{'a', 0xC3},
+		want: []byte{'a'},
+	}, {
+		name: "three byte rune cut after one",
+		in:   []byte{'a', 0xE2},
+		want: []byte{'a'},
+	}, {
+		name: "three byte rune cut after two",
+		in:   []byte{'a', 0xE2, 0x98},
+		want: []byte{'a'},
+	}, {
+		name: "four byte rune cut",
+		in:   []byte{'a', 0xF0, 0x9F, 0x92}, // U+1F4A9 cut
+		want: []byte{'a'},
+	}, {
+		name: "invalid start byte kept",
+		in:   []byte{'a', 0xFF},
+		want: []byte{'a', 0xFF},
+	}, {
+		name: "orphan continuation bytes kept",
+		in:   []byte{0x80, 0x81, 0x82, 0x83, 0x84},
+		want: []byte{0x80, 0x81, 0x82, 0x83, 0x84},
+	}, {
+		name: "truncated sequence followed by junk kept",
+		in:   []byte{0xE2, 0x98, 0xFF},
+		want: []byte{0xE2, 0x98, 0xFF},
+	}, {
+		name: "empty",
+		in:   []byte{},
+		want: []byte{},
+	}}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			assert.Equal(
+				t, tc.want,
+				handlers.TrimPartialRuneForTest(tc.in),
+			)
+		})
+	}
+}

internal/handlers/export_test.go

@@ -3,8 +3,35 @@ package handlers
 import (
 	"html/template"
 	"net/http"
+
+	"sneak.berlin/go/webhooker/internal/database"
 )
 
+// MaxRenderedBodyBytesForTest exposes the event log's body cap
+// to the handlers_test package.
+const MaxRenderedBodyBytesForTest = maxRenderedBodyBytes
+
+// TrimPartialRuneForTest exposes trimPartialRune for use in the
+// handlers_test package.
+func TrimPartialRuneForTest(b []byte) []byte {
+	return trimPartialRune(b)
+}
+
+// LoadEventLogViewsForTest exposes loadEventsWithDeliveries for
+// use in the handlers_test package. Assertions on the projected
+// body need the bytes as loaded: html/template rewrites invalid
+// UTF-8 on the way out, so the rendered page cannot show whether
+// a binary body survived the projection intact.
+func (s *Handlers) LoadEventLogViewsForTest(
+	w http.ResponseWriter,
+	webhook database.Webhook,
+	page int,
+) []EventLogView {
+	views, _ := s.loadEventsWithDeliveries(w, webhook, nil, page)
+
+	return views
+}
+
 // AddTemplateForTest registers a template under a page name so that
 // the handlers_test package can drive the render path with a
 // template of its own.

internal/handlers/handlers.go

@@ -229,8 +229,10 @@ func (s *Handlers) renderTemplate(
 // the response only once rendering has fully succeeded. Executing
 // straight into the ResponseWriter commits a partial body and a 200
 // status before a mid-render error can be reported, leaving no way
-// to serve a 500. These pages are small, so holding one in memory is
+// to serve a 500. Buffering makes a page's rendered size resident
-// the right trade.
+// memory per concurrent viewer, so every page owes it a bound: the
+// event log caps each stored body at maxRenderedBodyBytes for exactly
+// this reason.
 func (s *Handlers) executeTemplate(
 	w http.ResponseWriter,
 	tmpl *template.Template,

internal/handlers/source_detail_test.go

@@ -131,6 +131,47 @@ func TestHandleSourceDetail_MasksSlackWebhookURL(t *testing.T) {
 	assert.Contains(t, body, "https://hooks.slack.com/...")
 }
 
+// TestHandleSourceDetail_MasksHTTPDestinationURL is the
+// regression test for the same leak reached through the http
+// target: its destination is routinely an incoming-webhook
+// endpoint whose path segments are the credential, so the
+// rendered page must not contain them.
+func TestHandleSourceDetail_MasksHTTPDestinationURL(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	var (
+		h    *handlers.Handlers
+		sess *session.Session
+		db   *database.Database
+	)
+
+	app := newTestApp(t, &h, &sess, &db)
+	app.RequireStart()
+
+	t.Cleanup(app.RequireStop)
+
+	wh := seedWebhook(t, db)
+	seedConfiguredTarget(
+		t, db, wh.ID,
+		database.TargetTypeHTTP,
+		`{"url":"`+slackWebhookURL+`"}`,
+	)
+
+	body := renderSourceDetailPage(t, h, sess, wh.ID)
+
+	assert.NotContains(t, body, slackSecretPath)
+	assert.NotContains(t, body, "T00000000")
+	assert.NotContains(t, body, "B00000000")
+	assert.NotContains(
+		t, body, "XXXXXXXXXXXXXXXXXXXXXXXX",
+	)
+
+	assert.Contains(t, body, "Destination URL")
+	assert.Contains(t, body, "https://hooks.slack.com/...")
+}
+
 // TestHandleSourceDetail_RendersNamedTargetFields proves the
 // other target types render labelled fields rather than the
 // stored blob.
@@ -172,7 +213,7 @@ func TestHandleSourceDetail_RendersNamedTargetFields(
 	body := renderSourceDetailPage(t, h, sess, wh.ID)
 
 	assert.Contains(t, body, "Destination URL")
-	assert.Contains(t, body, "https://example.com/hook")
+	assert.Contains(t, body, "https://example.com/...")
 	assert.Contains(t, body, "Timeout")
 	assert.Contains(t, body, "1 configured")
 	assert.NotContains(t, body, "sekrit")

internal/handlers/source_management.go

@@ -92,13 +92,6 @@ func parseRetentionDays(raw string, fallback int) (int, error) {
 	return v, nil
 }
 
-// EventWithDeliveries holds an event and its deliveries.
-type EventWithDeliveries struct {
-	database.Event
-
-	Deliveries []DeliveryView
-}
-
 // DeliveryView is the display-safe projection of a delivery
 // for the event log page. Its target is a TargetView, so the
 // stored configuration blob — which holds the target's
@@ -815,16 +808,18 @@ func (h *Handlers) parsePage(r *http.Request) int {
 }
 
 // loadEventsWithDeliveries loads paginated events and their
-// deliveries from the per-webhook database.
+// deliveries from the per-webhook database. Events come back
+// as capped projections rather than database.Event rows: see
+// eventLogColumns for why the cut happens in SQL.
 func (h *Handlers) loadEventsWithDeliveries(
 	w http.ResponseWriter,
 	webhook database.Webhook,
 	targetMap map[string]delivery.TargetView,
 	page int,
-) ([]EventWithDeliveries, int64) {
+) ([]EventLogView, int64) {
 	var totalEvents int64
 
-	var result []EventWithDeliveries
+	var result []EventLogView
 
 	if !h.dbMgr.DBExists(webhook.ID) {
 		return result, totalEvents
@@ -845,23 +840,25 @@ func (h *Handlers) loadEventsWithDeliveries(
 
 	offset := (page - 1) * paginationPerPage
 
-	var events []database.Event
+	var rows []eventLogRow
 
-	webhookDB.Where(
+	webhookDB.Model(&database.Event{}).Select(
+		eventLogColumns, maxRenderedBodyBytes,
+	).Where(
 		"webhook_id = ?", webhook.ID,
 	).Order("created_at DESC").Offset(offset).Limit(
 		paginationPerPage,
-	).Find(&events)
+	).Find(&rows)
 
-	result = make([]EventWithDeliveries, len(events))
+	result = make([]EventLogView, len(rows))
 
-	for i := range events {
+	for i := range rows {
-		result[i].Event = events[i]
+		result[i] = rows[i].view()
 
 		var deliveries []database.Delivery
 
 		webhookDB.Where(
-			"event_id = ?", events[i].ID,
+			"event_id = ?", rows[i].ID,
 		).Find(&deliveries)
 
 		result[i].Deliveries = newDeliveryViews(

internal/lifecycle/export_test.go

@@ -0,0 +1,21 @@
+package lifecycle
+
+import (
+	"context"
+	"log/slog"
+)
+
+// WaitDone exposes waitDone to the external test package. Only the
+// unexported waiter can be handed a channel that is already closed
+// before the call, which is the state the preamble exists for;
+// through WaitForShutdown the waiter goroutine may or may not have
+// closed the channel yet, so the case is not reachable
+// deterministically from outside.
+func WaitDone(
+	ctx context.Context,
+	log *slog.Logger,
+	component string,
+	done <-chan struct{},
+) error {
+	return waitDone(ctx, log, component, done)
+}

internal/lifecycle/lifecycle.go

@@ -38,6 +38,29 @@ func WaitForShutdown(
 		wg.Wait()
 	}()
 
+	return waitDone(ctx, log, component, done)
+}
+
+// waitDone waits for done to close, bounded by ctx.
+//
+// The non-blocking preamble is load-bearing. When the component has
+// already drained and ctx has already expired, both cases of the
+// bounded select are ready and Go picks between them uniformly at
+// random, so a clean shutdown would be reported as a timeout about
+// half the time. Draining wins: the goroutines are gone, and there
+// is nothing left for the operator to act on.
+func waitDone(
+	ctx context.Context,
+	log *slog.Logger,
+	component string,
+	done <-chan struct{},
+) error {
+	select {
+	case <-done:
+		return nil
+	default:
+	}
+
 	select {
 	case <-done:
 		return nil

internal/lifecycle/lifecycle_test.go

@@ -37,6 +37,57 @@ func TestWaitForShutdown_DrainedGroup(t *testing.T) {
 	)
 }
 
+// racePasses is how many times the both-cases-ready race is run.
+// Without the preamble each pass is an independent coin flip, so
+// the probability of the whole loop passing by luck is 2^-N: at
+// this N the test is deterministic in practice, and it involves no
+// wall-clock waiting at all.
+const racePasses = 1000
+
+// TestWaitDone_DrainedBeforeExpiredContext covers the case where a
+// component drained cleanly but the stop context had already
+// expired. Both select cases are ready, and Go chooses among ready
+// cases uniformly at random, so the drained case must be settled by
+// the preamble before the bounded select ever runs.
+func TestWaitDone_DrainedBeforeExpiredContext(t *testing.T) {
+	t.Parallel()
+
+	done := make(chan struct{})
+	close(done)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	for pass := range racePasses {
+		require.NoErrorf(
+			t,
+			lifecycle.WaitDone(
+				ctx, discardLogger(), "test component", done,
+			),
+			"pass %d reported a timeout for a drained component",
+			pass,
+		)
+	}
+}
+
+// TestWaitDone_ExpiredContext pins the other side of the preamble:
+// an expired context with a component that has not drained is still
+// a timeout.
+func TestWaitDone_ExpiredContext(t *testing.T) {
+	t.Parallel()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	err := lifecycle.WaitDone(
+		ctx, discardLogger(), "test component",
+		make(chan struct{}),
+	)
+
+	require.ErrorIs(t, err, context.Canceled)
+	require.ErrorContains(t, err, "test component")
+}
+
 func TestWaitForShutdown_ContextExpires(t *testing.T) {
 	t.Parallel()
 

internal/server/server.go

@@ -24,9 +24,15 @@ import (
 )
 
 const (
-	// shutdownTimeout is the maximum time to wait for the HTTP
+	// ShutdownTimeout is the maximum time to wait for the HTTP
 	// server to finish in-flight requests during shutdown.
-	shutdownTimeout = 5 * time.Second
+	//
+	// It must stay strictly below the fx stop timeout in
+	// cmd/webhooker, which bounds the whole stop sequence: a drain
+	// that used the entire sequence budget would leave nothing for
+	// the hooks that run after the server, including the database
+	// close. It is exported so that relationship can be tested.
+	ShutdownTimeout = 3 * time.Second
 
 	// sentryFlushTimeout is the maximum time to wait for Sentry
 	// to flush pending events during shutdown.
@@ -164,7 +170,7 @@ func (s *Server) cleanShutdown(ctx context.Context) {
 	s.exitCode = 0
 
 	ctxShutdown, shutdownCancel := context.WithTimeout(
-		ctx, shutdownTimeout,
+		ctx, ShutdownTimeout,
 	)
 	defer shutdownCancel()
 

internal/server/static_assets_test.go

@@ -0,0 +1,50 @@
+package server_test
+
+import (
+	"net/http"
+	"regexp"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"sneak.berlin/go/webhooker/templates"
+)
+
+// TestBaseTemplateScriptsAreServed walks every /s/ script the base
+// template loads on each page and fetches it through the real router.
+// Alpine.js is fetched at build time rather than committed, so nothing
+// in the repo guarantees it is present: this is the check that the page
+// still gets the JavaScript it asks for.
+func TestBaseTemplateScriptsAreServed(t *testing.T) {
+	t.Parallel()
+
+	// scriptSrc matches the src of every <script> tag pointing at the
+	// /s/ static mount.
+	scriptSrc := regexp.MustCompile(`<script[^>]+src="(/s/[^"]+)"`)
+
+	base, err := templates.Templates.ReadFile("base.html")
+	require.NoError(t, err)
+
+	matches := scriptSrc.FindAllStringSubmatch(string(base), -1)
+	require.NotEmpty(t, matches, "base.html should load scripts from /s/")
+
+	env := newTestEnv(t)
+
+	for _, m := range matches {
+		src := m[1]
+		t.Run(src, func(t *testing.T) {
+			t.Parallel()
+
+			w := env.get(src, nil)
+
+			require.Equalf(
+				t, http.StatusOK, w.Code,
+				"base.html loads %s but the server does not serve it", src,
+			)
+			assert.NotEmptyf(
+				t, w.Body.Bytes(), "%s is served but empty", src,
+			)
+		})
+	}
+}

script/bootstrap

@@ -5,7 +5,8 @@
 # or apk (detected in that order); assumes NOTHING is present (not git,
 # make, or go). golangci-lint is packaged in nix, brew, and apk; on apt
 # it is installed from a hash-verified GitHub release archive (never
-# curl | sh).
+# curl | sh). Finishes by running script/fetch-assets, which installs the
+# hash-pinned third-party browser assets the repo does not commit.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
@@ -115,6 +116,11 @@ main() {
 
     go mod download
 
+    # Third-party browser assets are not committed; fetch and verify them
+    # so a fresh clone can build and test.
+    if missing curl; then pkg_install curl curl curl curl; fi
+    "$ROOT/script/fetch-assets"
+
     echo "bootstrap complete"
 }
 

script/fetch-assets

@@ -0,0 +1,104 @@
+#!/bin/sh
+# script/fetch-assets: download the third-party browser assets the web UI
+# ships and install them under static/. Minified bundles are not committed
+# (REPO_POLICIES.md: no build artifacts in version control), so the build
+# fetches them here. Every download is verified against a hardcoded sha256
+# before it is installed, and any mismatch aborts. Idempotent: an asset
+# already present with its pinned hash is left alone.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+# The sha256 of each installed asset lives in static/vendor.sha256, in
+# sha256sum(1) format, with paths relative to static/. That file is the
+# single source of truth: this script verifies against it, and
+# static/vendor_test.go asserts the bytes embedded into the binary match
+# it, so the hash cannot rot into a value nothing checks.
+MANIFEST="static/vendor.sha256"
+
+# Alpine.js 3.14.9, 2026-08-17. Fetched from registry.npmjs.org, the
+# publisher of record; the jsDelivr and unpkg copies are mirrors of this
+# same tarball. dist/cdn.min.js is the browser build Alpine publishes for
+# a <script> tag.
+ALPINE_VERSION="3.14.9"
+ALPINE_URL="https://registry.npmjs.org/alpinejs/-/alpinejs-${ALPINE_VERSION}.tgz"
+# sha256 of alpinejs-3.14.9.tgz
+ALPINE_TARBALL_SHA256="97dad7c0c81e659cfc8e7700055da9770f8186187cb9a8a76efb57e00d5ce52a"
+ALPINE_MEMBER="package/dist/cdn.min.js"
+ALPINE_DEST="js/alpine.min.js"
+
+sha256_of() {
+    if command -v sha256sum >/dev/null 2>&1; then
+        sha256sum "$1" | cut -d' ' -f1
+    else
+        shasum -a 256 "$1" | cut -d' ' -f1
+    fi
+}
+
+# expected_sha256 <path-relative-to-static>
+expected_sha256() {
+    awk -v want="$1" '$2 == want { print $1; found = 1 }
+        END { if (!found) exit 1 }' "$ROOT/$MANIFEST"
+}
+
+# verify <file> <expected-sha256> <what>
+verify() {
+    actual="$(sha256_of "$1")"
+    if [ "$actual" != "$2" ]; then
+        echo "fetch-assets: sha256 mismatch for $3" >&2
+        echo "  expected: $2" >&2
+        echo "  actual:   $actual" >&2
+        exit 1
+    fi
+}
+
+# up_to_date <path-relative-to-static> <expected-sha256>
+up_to_date() {
+    [ -f "$ROOT/static/$1" ] || return 1
+    [ "$(sha256_of "$ROOT/static/$1")" = "$2" ]
+}
+
+fetch_alpine() {
+    want="$(expected_sha256 "$ALPINE_DEST")"
+
+    if up_to_date "$ALPINE_DEST" "$want"; then
+        echo "fetch-assets: static/$ALPINE_DEST already at $want"
+        return 0
+    fi
+
+    echo "fetch-assets: fetching Alpine.js $ALPINE_VERSION from $ALPINE_URL"
+    tmp="$(mktemp -d)"
+    trap 'rm -rf "$tmp"' EXIT INT TERM
+    curl -fsSL -o "$tmp/alpine.tgz" "$ALPINE_URL"
+    verify "$tmp/alpine.tgz" "$ALPINE_TARBALL_SHA256" "alpinejs-${ALPINE_VERSION}.tgz"
+    tar -xzOf "$tmp/alpine.tgz" "$ALPINE_MEMBER" >"$tmp/alpine.min.js"
+    verify "$tmp/alpine.min.js" "$want" "$ALPINE_MEMBER from alpinejs-${ALPINE_VERSION}.tgz"
+
+    mkdir -p "$(dirname "$ROOT/static/$ALPINE_DEST")"
+    cp "$tmp/alpine.min.js" "$ROOT/static/$ALPINE_DEST"
+    rm -rf "$tmp"
+    trap - EXIT INT TERM
+    echo "fetch-assets: installed static/$ALPINE_DEST ($want)"
+}
+
+# Re-check every manifest entry against what is now on disk, so an entry
+# no script installs fails loudly instead of passing silently.
+verify_manifest() {
+    while read -r want path; do
+        case "$want" in '' | '#'*) continue ;; esac
+        if [ ! -f "$ROOT/static/$path" ]; then
+            echo "fetch-assets: $MANIFEST lists static/$path, which is missing" >&2
+            exit 1
+        fi
+        verify "$ROOT/static/$path" "$want" "static/$path"
+    done <"$ROOT/$MANIFEST"
+}
+
+main() {
+    cd "$ROOT"
+    fetch_alpine
+    verify_manifest
+    echo "fetch-assets: all assets in $MANIFEST verified"
+}
+
+main "$@"

static/vendor.sha256

@@ -0,0 +1 @@
+3ed1eed252488921df65e363d6715deb04d7f92aaedb9e52199fdf73cb1e0ad3  js/alpine.min.js

static/vendor_test.go

@@ -0,0 +1,92 @@
+package static_test
+
+import (
+	"bufio"
+	"crypto/sha256"
+	"encoding/hex"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"sneak.berlin/go/webhooker/static"
+)
+
+const manifestPath = "vendor.sha256"
+
+// fetchHint is appended to every failure here: the assets the manifest
+// covers are fetched by the build, not committed, so a fresh clone that
+// has not run script/fetch-assets fails this test and should be told why.
+const fetchHint = "run `script/fetch-assets` (or `make assets`) to install " +
+	"the pinned third-party assets"
+
+// TestVendoredAssetsMatchManifest asserts that every asset listed in
+// static/vendor.sha256 is embedded in the binary with exactly the pinned
+// bytes. script/fetch-assets verifies the same hashes at download time;
+// this test verifies them again on what actually ships, so a build that
+// skipped, cached, or subverted the fetch cannot produce a binary serving
+// unpinned third-party JavaScript.
+func TestVendoredAssetsMatchManifest(t *testing.T) {
+	t.Parallel()
+
+	entries := readManifest(t)
+	require.NotEmpty(t, entries, "%s lists no assets", manifestPath)
+
+	for path, want := range entries {
+		t.Run(path, func(t *testing.T) {
+			t.Parallel()
+
+			data, err := static.Static.ReadFile(path)
+			require.NoErrorf(
+				t, err,
+				"%s is listed in %s but is not embedded; %s",
+				path, manifestPath, fetchHint,
+			)
+
+			sum := sha256.Sum256(data)
+			got := hex.EncodeToString(sum[:])
+			require.Equalf(
+				t, want, got,
+				"embedded %s does not match its pinned sha256 in %s; %s",
+				path, manifestPath, fetchHint,
+			)
+		})
+	}
+}
+
+// readManifest parses static/vendor.sha256, which is in sha256sum(1)
+// format with paths relative to static/.
+func readManifest(t *testing.T) map[string]string {
+	t.Helper()
+
+	f, err := os.Open(manifestPath)
+	require.NoError(t, err, "opening %s", manifestPath)
+
+	defer func() { require.NoError(t, f.Close()) }()
+
+	entries := make(map[string]string)
+	scanner := bufio.NewScanner(f)
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		fields := strings.Fields(line)
+		require.Lenf(
+			t, fields, 2,
+			"%s: malformed entry %q, want \"<sha256>  <path>\"",
+			manifestPath, line,
+		)
+
+		sum, path := fields[0], fields[1]
+		require.Lenf(t, sum, 64, "%s: %q is not a sha256", manifestPath, sum)
+		entries[path] = sum
+	}
+
+	require.NoError(t, scanner.Err(), "reading %s", manifestPath)
+
+	return entries
+}

templates/source_logs.html

@@ -37,6 +37,9 @@
 
                 <div x-show="open" x-cloak class="mt-3 p-3 bg-gray-50 rounded-md">
                     <pre class="text-xs text-gray-700 overflow-x-auto whitespace-pre-wrap break-all">{{.Body}}</pre>
+                    {{if .BodyTruncated}}
+                    <p class="mt-2 text-xs text-gray-500">Body truncated for display: showing {{.BodyShownBytes}} of {{.BodyBytes}} bytes. The stored body is unchanged.</p>
+                    {{end}}
                 </div>
             </div>
             {{else}}