Correct release-blocking documentation inaccuracies (closes #141)

Four defects found by the integration review, each of which would have
made the README or the release notes untrue at the moment of tagging.

RETENTION_SWEEP_INTERVAL was absent from the README env table while two
other passages referred to it as documented. Enumerated every variable
read by internal/config from the source (12 in total) rather than by
eye; that was the only one missing.

TODO.md omitted five of the units landed in this milestone (#64, #79,
#90, #113, #118), two of them credential-exposure fixes, which are
precisely the entries a reader of the release notes wants to find. The
list is now derived from git log origin/main..origin/next.

The README sold Replay in the present tense as a core capability while
no redelivery code exists anywhere in the tree, and the roadmap entry
for it had been dropped without it being implemented. Every mention of
replay or redelivery in the README is now either marked planned or
already under a Planned heading: the Rationale item, the Use Cases
bullet, the Event model's field description, and the delivery-semantics
passage on target-type edits, which told an operator that a terminally
failed delivery was recoverable by hand when nothing can recover it.
The comment on failUnretryableRetry made the same claim and is
corrected with it. The roadmap entry is back in TODO.md.

The production JS asset shipped a console.log on load. The rest of the
file and every other shipped asset were checked; that was the only one
(alpine.min.js is vendored and untouched).

No behavioural change: the only non-comment, non-documentation edit is
the deleted console.log.

README.md

@@ -93,6 +93,7 @@ TTY detection, and security headers are always applied.
 | `METRICS_USERNAME`      | Basic auth username for `/metrics`  | `""`     |
 | `METRICS_PASSWORD`      | Basic auth password for `/metrics`  | `""`     |
 | `SENTRY_DSN`            | Sentry error reporting DSN          | `""`     |
+| `RETENTION_SWEEP_INTERVAL` | How often the retention reaper and archive sweeper run (Go duration, must be positive) | `1h` |
 | `SESSION_IDLE_TIMEOUT`  | Idle session timeout (Go duration)  | `24h`    |
 | `RECEIVER_RATE_LIMIT`   | Receiver requests/minute per IP per entrypoint | `120` |
 | `TRUSTED_PROXIES`       | CIDRs whose forwarded headers are trusted | `""` (none) |
@@ -173,8 +174,12 @@ its value and refuses to start, rather than silently running with a
 substituted default. `PORT=eighty`, `DEBUG=ture`, and
 `RETENTION_SWEEP_INTERVAL=1 hour` all abort startup. `PORT` must
 additionally be a number in the range 1–65535,
-`RECEIVER_RATE_LIMIT` must be at least 1, and every entry in
+`RECEIVER_RATE_LIMIT` must be at least 1,
-`TRUSTED_PROXIES` must be a CIDR block or a bare IP address.
+`RETENTION_SWEEP_INTERVAL` must be greater than zero (it is a ticker
+period, so `0s` or a negative value would crash the reaper after
+startup), and every entry in `TRUSTED_PROXIES` must be a CIDR block or
+a bare IP address. `SESSION_IDLE_TIMEOUT` is the exception: a
+non-positive value there means idle expiry is disabled, not invalid.
 
 Boolean variables (`DEBUG`, `MAINTENANCE_MODE`) accept exactly the
 spellings Go's `strconv.ParseBool` accepts — `1`, `t`, `T`, `TRUE`,
@@ -260,9 +265,10 @@ webhooker solves this by acting as a durable intermediary:
    targets simultaneously. This enables patterns like forwarding a
    GitHub webhook to both a deployment service and a Slack channel.
 
-5. **Replay** — Stored events can be manually redelivered for debugging
+5. **Replay** (not yet implemented) — Every received event is stored in
-   or testing, without requiring the original sender to fire the webhook
+   full, which is what manual redelivery for debugging or testing will
-   again.
+   be built on. No redelivery exists today, in the web UI or the API;
+   see [TODO.md](TODO.md).
 
 ### Use Cases
 
@@ -272,6 +278,7 @@ webhooker solves this by acting as a durable intermediary:
   size, and delivery performance
 - **Debugging** and introspection of webhook payloads in the web UI
 - **Replay** of webhook events for application testing and development
+  (planned; not yet implemented)
 - **Fan-out** delivery of a single webhook to multiple downstream
   targets
 - **High-availability ingestion** for delivery to less reliable backend
@@ -497,7 +504,7 @@ A programmatic access credential for API authentication.
 #### Event
 
 A captured incoming webhook request. Stores the complete HTTP request
-data for replay and auditing.
+data for auditing and for the planned replay capability.
 
 | Field          | Type   | Description |
 | -------------- | ------ | ----------- |
@@ -779,9 +786,10 @@ unknown) one while one of its deliveries is still `retrying`, both
 recovery paths above terminally mark that delivery `failed` and record a
 `DeliveryResult` naming the current target type as the reason, logging it
 at warn level. The delivery is not re-dispatched under the new type — the
-operator never asked for that delivery — and the event itself remains
+operator never asked for that delivery — and while the event itself
-stored in the per-webhook event database, so it can be redelivered
+remains stored in the per-webhook event database, there is no way to
-manually.
+redeliver it: manual redelivery is planned, not implemented (see
+[TODO.md](TODO.md)).
 
 ### Circuit Breaker (HTTP Targets with Retries)
 

TODO.md

@@ -61,6 +61,34 @@ rests on.
   Profile settings placeholder removed, a progressive-enhancement copy
   button for the entrypoint URL, and retention form copy that states the
   actual policy (deletion by the reaper, 0 retains forever) (#57)
+- 2026-08-11 Mask the webhook credential in delivery errors and logs:
+  Go embeds the request URL in `*url.Error`, so every transport failure
+  persisted the full Slack webhook URL into the per-webhook event
+  database via `DeliveryResult.Error`, a field a future REST API would
+  have served. `maskURLError` drops path, query and userinfo while
+  preserving the wrapped cause, so `errors.Is`/`As` and `Timeout()`
+  still work and DNS, TLS and timeout failures still read differently
+  (#118)
+- 2026-08-11 Rate-limit the public webhook receiver endpoint
+  (`RECEIVER_RATE_LIMIT`, default 120/min), keyed on client IP plus
+  entrypoint path so one entrypoint cannot exhaust another's budget;
+  over-limit requests get 429 with `Retry-After`. It was the one
+  unauthenticated, internet-facing endpoint with no limit at all (#64)
+- 2026-08-11 Enforce the body size limit before CSRF parses the form:
+  `MaxBodySize` is now first in all four form-parsing route groups, so
+  an oversized request is rejected with 413 instead of being read in
+  full by the CSRF middleware before any cap applied (#90)
+- 2026-08-11 Mask target config on the source detail page, which
+  rendered the stored blob verbatim and so exposed the Slack
+  incoming-webhook URL — a bearer credential that cannot be revoked
+  per-holder. Config reaches the template only as a `TargetView` of
+  labelled fields, and header values are rendered as a count (#113)
+- 2026-08-11 Allow `retention_days` of 0 to mean retain forever, via a
+  sentinel written in `BeforeSave` so the GORM column default cannot
+  win the race. Also bounds the reaper's cutoff arithmetic: day counts
+  above 106751 overflowed `time.Duration` and wrapped the cutoff into
+  the future, where every row matched and the sweep deleted everything
+  (#79)
 - 2026-08-09 Inactivity-based session timeout: sliding idle expiry
   (`SESSION_IDLE_TIMEOUT`, default `24h`) refreshed on authenticated
   requests, with the 7-day absolute cap kept as an independent
@@ -115,6 +143,9 @@ rests on.
 
 # Future Steps
 
+- Manual event redelivery from the web UI — the "Replay" capability the
+  README describes as planned. No redelivery code exists anywhere in the
+  tree; events are stored in full, which is all it would be built on
 - Delivery status and retry management UI
 - Per-webhook rate limiting in the receiver handler (per-webhook config
   plus handler enforcement; global limits must not apply to receiver

internal/config/config.go

@@ -92,6 +92,7 @@ type Config struct {
 	SentryDSN       string
 
 	// RetentionSweepInterval is how often the retention reaper runs.
+	// Always positive: it becomes a time.NewTicker period.
 	RetentionSweepInterval time.Duration
 
 	// SessionIdleTimeout is the sliding inactivity window after
@@ -235,6 +236,34 @@ func envDuration(
 	return d, nil
 }
 
+// envPositiveDuration returns the value of the named environment
+// variable parsed as a Go duration that must be greater than zero.
+// Returns defaultValue if not set. A set value that is unparseable or
+// non-positive is a hard error naming the key and the bad value.
+//
+// This is for durations that reach time.NewTicker, which panics on a
+// non-positive period, in a goroutine started after startup has
+// already reported success. It is deliberately not used for durations
+// where non-positive means "disabled" (SESSION_IDLE_TIMEOUT).
+func envPositiveDuration(
+	key string,
+	defaultValue time.Duration,
+) (time.Duration, error) {
+	d, err := envDuration(key, defaultValue)
+	if err != nil {
+		return 0, err
+	}
+
+	if d <= 0 {
+		return 0, fmt.Errorf(
+			"%w: %s must be greater than zero, got %s",
+			ErrNonPositiveValue, key, d,
+		)
+	}
+
+	return d, nil
+}
+
 // parseCIDR parses one trusted-proxy list entry, which may be a
 // CIDR block ("10.0.0.0/8") or a bare address ("10.0.0.1", treated
 // as a single-host block).
@@ -346,7 +375,7 @@ func loadFromEnv() (*Config, error) {
 		return nil, err
 	}
 
-	retentionSweepInterval, err := envDuration(
+	retentionSweepInterval, err := envPositiveDuration(
 		"RETENTION_SWEEP_INTERVAL",
 		defaultRetentionSweepInterval,
 	)
@@ -354,6 +383,8 @@ func loadFromEnv() (*Config, error) {
 		return nil, err
 	}
 
+	// Non-positive is "disabled" here, not invalid, so this stays on
+	// envDuration.
 	sessionIdleTimeout, err := envDuration(
 		"SESSION_IDLE_TIMEOUT",
 		defaultSessionIdleTimeout,

internal/config/config_test.go

@@ -139,7 +139,11 @@ func TestRetentionSweepInterval(t *testing.T) {
 		set         bool
 		value       string
 		expectError bool
-		expected    time.Duration
+		// sentinel, when set, must be wrapped by the startup
+		// error; every error case must additionally name the
+		// variable in its message.
+		sentinel error
+		expected time.Duration
 	}{
 		{
 			name:     caseUnsetUsesDefault,
@@ -158,6 +162,24 @@ func TestRetentionSweepInterval(t *testing.T) {
 			value:       "not-a-duration",
 			expectError: true,
 		},
+		{
+			// A non-positive period panics the ticker in the
+			// reaper and archive-sweeper goroutines, long after
+			// startup has reported success, so it has to fail
+			// here instead.
+			name:        "zero fails startup",
+			set:         true,
+			value:       "0s",
+			expectError: true,
+			sentinel:    config.ErrNonPositiveValue,
+		},
+		{
+			name:        "negative fails startup",
+			set:         true,
+			value:       "-1h",
+			expectError: true,
+			sentinel:    config.ErrNonPositiveValue,
+		},
 	}
 
 	for _, tt := range tests {
@@ -175,7 +197,9 @@ func TestRetentionSweepInterval(t *testing.T) {
 			}
 
 			if tt.expectError {
-				expectStartupError(t)
+				expectStartupErrorFor(
+					t, "RETENTION_SWEEP_INTERVAL", tt.sentinel,
+				)
 			} else {
 				testRetentionSweepIntervalSuccess(t, tt.expected)
 			}
@@ -281,6 +305,22 @@ func TestSessionIdleTimeout(t *testing.T) {
 			value:       "not-a-duration",
 			expectError: true,
 		},
+		{
+			// Non-positive is "idle expiry disabled" for this
+			// variable, not a configuration error: unlike
+			// RETENTION_SWEEP_INTERVAL it never becomes a ticker
+			// period.
+			name:     "zero disables idle expiry",
+			set:      true,
+			value:    "0s",
+			expected: 0,
+		},
+		{
+			name:     "negative disables idle expiry",
+			set:      true,
+			value:    "-1h",
+			expected: -time.Hour,
+		},
 	}
 
 	for _, tt := range tests {

internal/delivery/engine.go

@@ -785,9 +785,9 @@ func (e *Engine) sweepSingleRetry(
 // status retrying themselves. Re-dispatching under the new type
 // would be a delivery the operator never asked for, and leaving
 // the row retrying strands it forever, so the delivery is
-// failed with a recorded reason and can be redelivered
+// failed with a recorded reason. The event stays stored, but
-// manually. Logged at warn, not error: this is operator-caused
+// nothing redelivers it today. Logged at warn, not error: this
-// state, not a system fault.
+// is operator-caused state, not a system fault.
 func (e *Engine) failUnretryableRetry(
 	webhookDB *gorm.DB,
 	webhookID string,

static/js/app.js

@@ -1,5 +1,4 @@
 // Webhooker client-side JavaScript
-console.log("Webhooker loaded");
 
 // Copy-to-clipboard, as progressive enhancement.
 //