Merge remote-tracking branch 'origin/main' into feature/resolver

# Conflicts:
#	internal/resolver/errors.go
#	internal/resolver/resolver.go
#	internal/resolver/resolver_test.go

.golangci.yml

@@ -1,9 +1,5 @@
 version: "2"
 
-# Config schema uses the golangci-lint v2 layout (settings live under
-# linters.settings, not top-level linters-settings) so that the
-# thresholds below are actually applied by golangci-lint >= v2.
-
 run:
   timeout: 5m
   modules-download-mode: readonly
@@ -18,7 +14,8 @@ linters:
     - wsl              # Deprecated, replaced by wsl_v5
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
-  settings:
+
+linters-settings:
   lll:
     line-length: 88
   funlen:
@@ -30,5 +27,6 @@ linters:
     threshold: 100
 
 issues:
+  exclude-use-default: false
   max-issues-per-linter: 0
   max-same-issues: 0

Dockerfile

@@ -4,8 +4,8 @@ FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4
 
 RUN apk add --no-cache git make gcc musl-dev binutils-gold
 
-# golangci-lint v2.12.2, 2026-08-07
+# golangci-lint v2.10.1
-RUN go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@c0d3ddc9cf3faa61a4e378e879ece580256d76e5
+RUN go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee
 # goimports v0.42.0
 RUN go install golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0
 

README.md

@@ -17,26 +17,6 @@ without requiring an external database.
 
 ---
 
-## No DNS mocking. Ever.
-
-**DNS is never mocked in this project — not in tests, not anywhere else.**
-No mock resolvers, no fake DNS servers, no stubbed lookups.
-
-dnswatcher's entire purpose is correct behavior against the real DNS.
-Tests exercise real iterative resolution against live nameservers by
-design; a test suite that passes against a mock proves nothing about the
-one thing this program exists to do.
-
-When live tests are flaky, that is a robustness problem, and it gets
-fixed with robustness: retries with backoff, querying multiple
-independent nameservers, longer timeouts — or explicit opt-in gating
-decided by the project owner. Never with mocks.
-
-Contributions that introduce mocked, faked, or stubbed DNS will be
-rejected.
-
----
-
 ## Features
 
 ### DNS Domain Monitoring (Apex Domains)

TESTING.md

@@ -2,10 +2,8 @@
 
 ## DNS Resolution Tests
 
-All tests that involve DNS resolution — in every package, including
+All resolver tests **MUST** use live queries against real DNS servers.
-consumers of the resolver such as the watcher — **MUST** use live
+No mocking of the DNS client layer is permitted.
-queries against real DNS servers. No mocking, faking, or stubbing of
-DNS at any layer is permitted.
 
 ### Rationale
 
@@ -14,8 +12,6 @@ the full delegation chain. Mocked responses cannot faithfully represent
 the variety of real-world DNS behavior (truncation, referrals, glue
 records, DNSSEC, varied response times, EDNS, etc.). Testing against
 real servers ensures the resolver works correctly in production.
-Robustness comes from handling real-world DNS behavior with tolerant
-assertions and sensible timeouts, not from mocks.
 
 ### Constraints
 
@@ -28,14 +24,11 @@ assertions and sensible timeouts, not from mocks.
 - Flaky failures from transient network issues are acceptable and
   should be investigated as potential resolver bugs, not papered over
   with mocks or skip flags
-- Watcher change-detection tests seed a synthetic *previous state*
-  and compare it against fresh live lookups; the DNS side is never
-  faked
 
 ### What NOT to do
 
-- **Do not mock `DNSClient`**, the watcher's `DNSResolver` interface,
+- **Do not mock `DNSClient`** for resolver tests (the mock constructor
-  or any other DNS abstraction — in any package, for any reason
+  exists for unit-testing other packages that consume the resolver)
 - **Do not add `-short` flags** to skip slow tests
 - **Do not increase `-timeout`** to hide hanging queries
 - **Do not modify linter configuration** to suppress findings

TODO.md

@@ -14,10 +14,7 @@ pre-1.0. No git tags. Core resolver work in flight on feature/resolver
 (dirty: internal/resolver/resolver_test.go). Local checkout has diverged
 from origin: origin/main is 8 commits ahead (watcher orchestrator,
 unified TARGETS) and origin/feature/resolver already contains the full
-iterative resolver implementation. DNS mocking is banned in this repo
+iterative resolver implementation with hermetic mocked tests.
-(see `TESTING.md`): all tests use live DNS only. The hermetic mocked
-tests previously noted on `feature/resolver` are gone from its current
-tip, which carries a live-DNS suite against `*.dns.sneak.cloud`.
 
 # Next Step
 
@@ -28,23 +25,10 @@ confirm make check still passes.
 
 # Completed Steps
 
-- 2026-08-07: DNS mocking removed from the entire test suite; watcher
-  tests now drive the real iterative resolver against live DNS and
-  `TESTING.md` bans DNS mocks in every package (`remove-dns-mocking`
-  branch)
-- 2026-08-07: golangci-lint bumped to v2.12.2 (commit-pinned installs
-  in `Dockerfile` and `script/bootstrap`); `.golangci.yml` set to the
-  org-standard v2-schema config used across the org's repos
-  (owner-authorized; same file is being landed as canonical via prompts
-  PR #24), with settings under `linters.settings` so the
-  lll/funlen/cyclop/dupl thresholds apply; fixed the resulting
-  `goconst`, `dupl`, and `lll` findings; the informational `gomodguard`
-  deprecation warning under this config is accepted
 - 2026-07-07 Adopted scripts-to-rule-them-all: `script/` entrypoints,
   Makefile shims, README Entrypoints section
 - 2026-02-20: iterative DNS resolver implemented; tests made hermetic
-  with mocked DNS (origin/feature/resolver, unmerged; superseded — DNS
+  with mocked DNS (origin/feature/resolver, unmerged)
-  mocking is banned, see `TESTING.md`)
 - 2026-02-20: CI actions and go install refs pinned to commit SHAs;
   Gitea Actions workflow for make check (origin/ci/make-check, unmerged)
 - 2026-02-20: watcher monitoring orchestrator merged to main (#8)
@@ -71,9 +55,8 @@ Branch reconciliation:
 - Sync local checkout with origin: local main is 8 commits behind
   origin/main; local feature/resolver has diverged from
   origin/feature/resolver, which already implements the resolver
-- Merge in-flight branches to main once green: feature/resolver
+- Merge in-flight branches to main once green: feature/resolver,
-  (confirm its tests remain live-DNS — DNS mocking is banned, see
+  ci/make-check, feature/portcheck-implementation,
-  `TESTING.md`), ci/make-check, feature/portcheck-implementation,
   feature/tlscheck-implementation
 
 Resolver (plan from untracked TODO.md; largely implemented on
@@ -157,7 +140,6 @@ Infrastructure notes (from untracked TODO.md):
 - Module path sneak.berlin/go/dnswatcher differs from the git.eeqj.de
   remote intentionally; do not "fix" it
 - Dependencies: github.com/miekg/dns, golang.org/x/net/publicsuffix
-- Resolver tests originally used live DNS against `*.dns.sneak.cloud`
+- Resolver tests originally used live DNS against *.dns.sneak.cloud
-  (required records documented in the test file header); `main` now
+  (required records documented in the test file header); origin now has
-  tests against live public DNS. DNS mocking is banned (see
+  mocked hermetic tests, keep them hermetic
-  `TESTING.md`); never reintroduce hermetic mocked DNS tests

internal/config/classify_test.go

@@ -17,33 +17,13 @@ func TestClassifyDNSName(t *testing.T) {
 	}{
 		{name: "apex domain simple", input: "example.com", want: config.DNSNameTypeDomain},
 		{name: "hostname simple", input: "www.example.com", want: config.DNSNameTypeHostname},
-		{
+		{name: "apex domain multi-part TLD", input: "example.co.uk", want: config.DNSNameTypeDomain},
-			name:  "apex domain multi-part TLD",
+		{name: "hostname multi-part TLD", input: "api.example.co.uk", want: config.DNSNameTypeHostname},
-			input: "example.co.uk",
-			want:  config.DNSNameTypeDomain,
-		},
-		{
-			name:  "hostname multi-part TLD",
-			input: "api.example.co.uk",
-			want:  config.DNSNameTypeHostname,
-		},
 		{name: "public suffix itself", input: "co.uk", wantErr: true},
 		{name: "empty string", input: "", wantErr: true},
-		{
+		{name: "deeply nested hostname", input: "a.b.c.example.com", want: config.DNSNameTypeHostname},
-			name:  "deeply nested hostname",
+		{name: "trailing dot stripped", input: "example.com.", want: config.DNSNameTypeDomain},
-			input: "a.b.c.example.com",
+		{name: "uppercase normalized", input: "WWW.Example.COM", want: config.DNSNameTypeHostname},
-			want:  config.DNSNameTypeHostname,
-		},
-		{
-			name:  "trailing dot stripped",
-			input: "example.com.",
-			want:  config.DNSNameTypeDomain,
-		},
-		{
-			name:  "uppercase normalized",
-			input: "WWW.Example.COM",
-			want:  config.DNSNameTypeHostname,
-		},
 	}
 
 	for _, tt := range tests {

internal/notify/delivery_test.go

@@ -25,20 +25,6 @@ const (
 	colorDefault = "#6c757d"
 )
 
-// Priority strings used across multiple tests.
-const (
-	prioError   = "error"
-	prioWarning = "warning"
-	prioSuccess = "success"
-	prioInfo    = "info"
-	prioUnknown = "unknown"
-	prioDefault = "default"
-	prioUrgent  = "urgent"
-)
-
-// testHost is the hostname used in request construction tests.
-const testHost = "example.com"
-
 // errSimulated is a static error for transport failures.
 var errSimulated = errors.New("simulated transport failure")
 
@@ -115,13 +101,13 @@ func TestNtfyPriority(t *testing.T) {
 		input string
 		want  string
 	}{
-		{prioError, prioUrgent},
+		{"error", "urgent"},
-		{prioWarning, "high"},
+		{"warning", "high"},
-		{prioSuccess, prioDefault},
+		{"success", "default"},
-		{prioInfo, "low"},
+		{"info", "low"},
-		{"", prioDefault},
+		{"", "default"},
-		{prioUnknown, prioDefault},
+		{"unknown", "default"},
-		{"critical", prioDefault},
+		{"critical", "default"},
 	}
 
 	for _, tc := range cases {
@@ -148,12 +134,12 @@ func TestSlackColor(t *testing.T) {
 		input string
 		want  string
 	}{
-		{prioError, colorError},
+		{"error", colorError},
-		{prioWarning, colorWarning},
+		{"warning", colorWarning},
-		{prioSuccess, colorSuccess},
+		{"success", colorSuccess},
-		{prioInfo, colorInfo},
+		{"info", colorInfo},
 		{"", colorDefault},
-		{prioUnknown, colorDefault},
+		{"unknown", colorDefault},
 		{"critical", colorDefault},
 	}
 
@@ -179,7 +165,7 @@ func TestNewRequest(t *testing.T) {
 
 	target := &url.URL{
 		Scheme: "https",
-		Host:   testHost,
+		Host:   "example.com",
 		Path:   "/webhook",
 	}
 	body := bytes.NewBufferString("hello")
@@ -201,9 +187,9 @@ func TestNewRequest(t *testing.T) {
 		)
 	}
 
-	if req.Host != testHost {
+	if req.Host != "example.com" {
 		t.Errorf(
-			"Host = %q, want %q", req.Host, testHost,
+			"Host = %q, want %q", req.Host, "example.com",
 		)
 	}
 
@@ -231,7 +217,7 @@ func TestNewRequestPreservesContext(t *testing.T) {
 		ctxKey("k"),
 		"v",
 	)
-	target := &url.URL{Scheme: "https", Host: testHost}
+	target := &url.URL{Scheme: "https", Host: "example.com"}
 
 	req := notify.NewRequestForTest(
 		ctx, http.MethodGet, target, http.NoBody,
@@ -303,10 +289,10 @@ func TestSendNtfyHeaders(t *testing.T) {
 		)
 	}
 
-	if captured.priority != prioUrgent {
+	if captured.priority != "urgent" {
 		t.Errorf(
 			"Priority header = %q, want %q",
-			captured.priority, prioUrgent,
+			captured.priority, "urgent",
 		)
 	}
 
@@ -325,10 +311,10 @@ func TestSendNtfyAllPriorities(t *testing.T) {
 		input string
 		want  string
 	}{
-		{prioError, prioUrgent},
+		{"error", "urgent"},
-		{prioWarning, "high"},
+		{"warning", "high"},
-		{prioSuccess, prioDefault},
+		{"success", "default"},
-		{prioInfo, "low"},
+		{"info", "low"},
 	}
 
 	for _, tc := range priorities {
@@ -370,69 +356,56 @@ func TestSendNtfyAllPriorities(t *testing.T) {
 	}
 }
 
-// assertSendStatusError verifies that send returns an error
+func TestSendNtfyClientError(t *testing.T) {
-// wrapping wantErr when the server responds with status.
+	t.Parallel()
-func assertSendStatusError(
-	t *testing.T,
-	status int,
-	wantErr error,
-	send func(*notify.Service, *url.URL) error,
-) {
-	t.Helper()
 
 	srv := httptest.NewServer(
 		http.HandlerFunc(
 			func(w http.ResponseWriter, _ *http.Request) {
-				w.WriteHeader(status)
+				w.WriteHeader(http.StatusForbidden)
 			}),
 	)
 	defer srv.Close()
 
 	svc := notify.NewTestService(srv.Client().Transport)
-	target, _ := url.Parse(srv.URL)
+	topicURL, _ := url.Parse(srv.URL)
 
-	err := send(svc, target)
+	err := svc.SendNtfy(
+		context.Background(), topicURL, "t", "m", "info",
+	)
 	if err == nil {
-		t.Fatalf("expected error for %d response", status)
+		t.Fatal("expected error for 403 response")
 	}
 
-	if !errors.Is(err, wantErr) {
+	if !errors.Is(err, notify.ErrNtfyFailed) {
-		t.Errorf("error = %v, want %v", err, wantErr)
+		t.Errorf("error = %v, want ErrNtfyFailed", err)
 	}
 }
 
-func sendNtfyInfo(
-	svc *notify.Service, target *url.URL,
-) error {
-	return svc.SendNtfy(
-		context.Background(), target, "t", "m", prioInfo,
-	)
-}
-
-func sendSlackInfo(
-	svc *notify.Service, target *url.URL,
-) error {
-	return svc.SendSlack(
-		context.Background(), target, "t", "m", prioInfo,
-	)
-}
-
-func TestSendNtfyClientError(t *testing.T) {
-	t.Parallel()
-
-	assertSendStatusError(
-		t, http.StatusForbidden,
-		notify.ErrNtfyFailed, sendNtfyInfo,
-	)
-}
-
 func TestSendNtfyServerError(t *testing.T) {
 	t.Parallel()
 
-	assertSendStatusError(
+	srv := httptest.NewServer(
-		t, http.StatusInternalServerError,
+		http.HandlerFunc(
-		notify.ErrNtfyFailed, sendNtfyInfo,
+			func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusInternalServerError)
+			}),
 	)
+	defer srv.Close()
+
+	svc := notify.NewTestService(srv.Client().Transport)
+	topicURL, _ := url.Parse(srv.URL)
+
+	err := svc.SendNtfy(
+		context.Background(), topicURL, "t", "m", "info",
+	)
+	if err == nil {
+		t.Fatal("expected error for 500 response")
+	}
+
+	if !errors.Is(err, notify.ErrNtfyFailed) {
+		t.Errorf("error = %v, want ErrNtfyFailed", err)
+	}
 }
 
 func TestSendNtfySuccess(t *testing.T) {
@@ -577,11 +550,11 @@ func TestSendSlackAllColors(t *testing.T) {
 		priority string
 		want     string
 	}{
-		{prioError, colorError},
+		{"error", colorError},
-		{prioWarning, colorWarning},
+		{"warning", colorWarning},
-		{prioSuccess, colorSuccess},
+		{"success", colorSuccess},
-		{prioInfo, colorInfo},
+		{"info", colorInfo},
-		{prioUnknown, colorDefault},
+		{"unknown", colorDefault},
 	}
 
 	for _, tc := range colors {
@@ -633,19 +606,53 @@ func TestSendSlackAllColors(t *testing.T) {
 func TestSendSlackClientError(t *testing.T) {
 	t.Parallel()
 
-	assertSendStatusError(
+	srv := httptest.NewServer(
-		t, http.StatusBadRequest,
+		http.HandlerFunc(
-		notify.ErrSlackFailed, sendSlackInfo,
+			func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusBadRequest)
+			}),
 	)
+	defer srv.Close()
+
+	svc := notify.NewTestService(srv.Client().Transport)
+	webhookURL, _ := url.Parse(srv.URL)
+
+	err := svc.SendSlack(
+		context.Background(), webhookURL, "t", "m", "info",
+	)
+	if err == nil {
+		t.Fatal("expected error for 400 response")
+	}
+
+	if !errors.Is(err, notify.ErrSlackFailed) {
+		t.Errorf("error = %v, want ErrSlackFailed", err)
+	}
 }
 
 func TestSendSlackServerError(t *testing.T) {
 	t.Parallel()
 
-	assertSendStatusError(
+	srv := httptest.NewServer(
-		t, http.StatusBadGateway,
+		http.HandlerFunc(
-		notify.ErrSlackFailed, sendSlackInfo,
+			func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusBadGateway)
+			}),
 	)
+	defer srv.Close()
+
+	svc := notify.NewTestService(srv.Client().Transport)
+	webhookURL, _ := url.Parse(srv.URL)
+
+	err := svc.SendSlack(
+		context.Background(), webhookURL, "t", "m", "error",
+	)
+	if err == nil {
+		t.Fatal("expected error for 502 response")
+	}
+
+	if !errors.Is(err, notify.ErrSlackFailed) {
+		t.Errorf("error = %v, want ErrSlackFailed", err)
+	}
 }
 
 func TestSendSlackNetworkError(t *testing.T) {
@@ -970,62 +977,74 @@ func TestSendNotificationMattermostOnly(t *testing.T) {
 	}
 }
 
-// assertSendNotificationTolerates verifies SendNotification
+func TestSendNotificationNtfyError(t *testing.T) {
-// neither panics nor blocks when the endpoint configured by
+	t.Parallel()
-// setURL responds with status.
-func assertSendNotificationTolerates(
-	t *testing.T,
-	status int,
-	priority string,
-	setURL func(*notify.Service, *url.URL),
-) {
-	t.Helper()
 
 	srv := httptest.NewServer(
 		http.HandlerFunc(
 			func(w http.ResponseWriter, _ *http.Request) {
-				w.WriteHeader(status)
+				w.WriteHeader(http.StatusInternalServerError)
 			}),
 	)
 	defer srv.Close()
 
-	target, _ := url.Parse(srv.URL)
+	ntfyURL, _ := url.Parse(srv.URL)
 
 	svc := notify.NewTestService(http.DefaultTransport)
-	setURL(svc, target)
+	svc.SetNtfyURL(ntfyURL)
 
+	// Should not panic or block.
 	svc.SendNotification(
-		context.Background(), "t", "m", priority,
+		context.Background(), "t", "m", "error",
 	)
 
 	time.Sleep(100 * time.Millisecond)
 }
 
-func TestSendNotificationNtfyError(t *testing.T) {
-	t.Parallel()
-
-	assertSendNotificationTolerates(
-		t, http.StatusInternalServerError, prioError,
-		(*notify.Service).SetNtfyURL,
-	)
-}
-
 func TestSendNotificationSlackError(t *testing.T) {
 	t.Parallel()
 
-	assertSendNotificationTolerates(
+	srv := httptest.NewServer(
-		t, http.StatusForbidden, prioError,
+		http.HandlerFunc(
-		(*notify.Service).SetSlackWebhookURL,
+			func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusForbidden)
+			}),
 	)
+	defer srv.Close()
+
+	slackURL, _ := url.Parse(srv.URL)
+
+	svc := notify.NewTestService(http.DefaultTransport)
+	svc.SetSlackWebhookURL(slackURL)
+
+	svc.SendNotification(
+		context.Background(), "t", "m", "error",
+	)
+
+	time.Sleep(100 * time.Millisecond)
 }
 
 func TestSendNotificationMattermostError(t *testing.T) {
 	t.Parallel()
 
-	assertSendNotificationTolerates(
+	srv := httptest.NewServer(
-		t, http.StatusBadGateway, prioWarning,
+		http.HandlerFunc(
-		(*notify.Service).SetMattermostWebhookURL,
+			func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusBadGateway)
+			}),
 	)
+	defer srv.Close()
+
+	mmURL, _ := url.Parse(srv.URL)
+
+	svc := notify.NewTestService(http.DefaultTransport)
+	svc.SetMattermostWebhookURL(mmURL)
+
+	svc.SendNotification(
+		context.Background(), "t", "m", "warning",
+	)
+
+	time.Sleep(100 * time.Millisecond)
 }
 
 // ── SlackPayload JSON marshaling ──────────────────────────

internal/notify/history_test.go

@@ -29,14 +29,14 @@ func TestAlertHistoryAddAndRecent(t *testing.T) {
 		Timestamp: now.Add(-2 * time.Minute),
 		Title:     "first",
 		Message:   "msg1",
-		Priority:  prioInfo,
+		Priority:  "info",
 	})
 
 	h.Add(notify.AlertEntry{
 		Timestamp: now.Add(-1 * time.Minute),
 		Title:     "second",
 		Message:   "msg2",
-		Priority:  prioWarning,
+		Priority:  "warning",
 	})
 
 	entries := h.Recent()

internal/notify/retry.go

@@ -69,7 +69,7 @@ func (rc RetryConfig) backoff(attempt int) time.Duration {
 	lo := raw * (1 - jitterFraction)
 	hi := raw * (1 + jitterFraction)
 
-	jittered := lo + rand.Float64()*(hi-lo) //nolint:gosec // jitter needs no crypto/rand
+	jittered := lo + rand.Float64()*(hi-lo) //nolint:gosec // jitter does not need crypto/rand
 
 	return time.Duration(jittered)
 }

internal/resolver/dns_client.go

@@ -7,8 +7,8 @@ import (
 	"github.com/miekg/dns"
 )
 
-// DNSClient abstracts DNS wire-protocol exchanges over a single
+// DNSClient abstracts DNS wire-protocol exchanges so the resolver
-// transport, letting the resolver switch between UDP and TCP.
+// can be tested without hitting real nameservers.
 type DNSClient interface {
 	ExchangeContext(
 		ctx context.Context,

internal/resolver/resolver.go

@@ -67,4 +67,17 @@ func NewFromLogger(log *slog.Logger) *Resolver {
 	}
 }
 
+// NewFromLoggerWithClient creates a Resolver with a custom DNS
+// client, useful for testing with mock DNS responses.
+func NewFromLoggerWithClient(
+	log *slog.Logger,
+	client DNSClient,
+) *Resolver {
+	return &Resolver{
+		log:    log,
+		client: client,
+		tcp:    client,
+	}
+}
+
 // Method implementations are in iterative.go.

internal/resolver/resolver_test.go

@@ -1,3 +1,10 @@
+// Package resolver_test verifies the iterative resolver against
+// live DNS. Per TESTING.md, all resolver tests use real queries
+// against real nameservers — no mocking of the DNS client layer.
+// Tests target long-lived public infrastructure (root servers,
+// gTLD servers, IANA, Google, Cloudflare, GitHub) to minimize
+// fixture churn, plus dedicated fixture records in the
+// sneak.cloud zone.
 package resolver_test
 
 import (
@@ -16,6 +23,30 @@ import (
 	"sneak.berlin/go/dnswatcher/internal/resolver"
 )
 
+// ----------------------------------------------------------------
+// Test fixtures
+// ----------------------------------------------------------------
+
+// Fixture hostnames in the sneak.cloud zone (hosted on
+// Cloudflare). These records must exist in the sneak.cloud zone:
+//
+//	basic.dns.sneak.cloud         A      192.0.2.1
+//	multi.dns.sneak.cloud         A      192.0.2.1
+//	multi.dns.sneak.cloud         A      192.0.2.2
+//	ipv6.dns.sneak.cloud          AAAA   2001:db8::1
+//	dual.dns.sneak.cloud          A      192.0.2.1
+//	dual.dns.sneak.cloud          AAAA   2001:db8::1
+//	cname-target.dns.sneak.cloud  A      198.51.100.1
+//	cname.dns.sneak.cloud         CNAME  cname-target.dns.sneak.cloud
+const (
+	testDomain        = "sneak.cloud"
+	testHostBasic     = "basic.dns.sneak.cloud"
+	testHostMultiA    = "multi.dns.sneak.cloud"
+	testHostIPv6      = "ipv6.dns.sneak.cloud"
+	testHostDualStack = "dual.dns.sneak.cloud"
+	testHostCNAME     = "cname.dns.sneak.cloud"
+)
+
 // ----------------------------------------------------------------
 // Test helpers
 // ----------------------------------------------------------------
@@ -107,6 +138,35 @@ func TestFindAuthoritativeNameservers_Subdomain(
 	require.NotEmpty(t, nameservers)
 }
 
+func TestFindAuthoritativeNameservers_TLD(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	nameservers, err := r.FindAuthoritativeNameservers(
+		ctx, "com",
+	)
+	require.NoError(t, err)
+	require.NotEmpty(t, nameservers,
+		"should find TLD nameservers",
+	)
+
+	hasGTLD := false
+
+	for _, ns := range nameservers {
+		if strings.Contains(ns, "gtld-servers.net") {
+			hasGTLD = true
+
+			break
+		}
+	}
+
+	assert.True(t, hasGTLD,
+		"expected gtld-servers for com, got: %v", nameservers,
+	)
+}
+
 func TestFindAuthoritativeNameservers_ReturnsSorted(
 	t *testing.T,
 ) {
@@ -190,6 +250,68 @@ func TestFindAuthoritativeNameservers_CloudflareDomain(
 	}
 }
 
+func TestFindAuthoritativeNameservers_AllNSRespondAuthoritatively(
+	t *testing.T,
+) {
+	// Every NS returned by FindAuthoritativeNameservers must
+	// actually serve the zone. A lame NS would return REFUSED,
+	// SERVFAIL, or a non-authoritative answer.
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	nameservers, err := r.FindAuthoritativeNameservers(
+		ctx, "google.com",
+	)
+	require.NoError(t, err)
+	require.NotEmpty(t, nameservers)
+
+	for _, ns := range nameservers {
+		resp, queryErr := r.QueryNameserver(
+			ctx, ns, "www.google.com",
+		)
+		require.NoError(t, queryErr,
+			"NS %s should be queryable", ns,
+		)
+		assert.Equal(
+			t, resolver.StatusOK, resp.Status,
+			"NS %s should respond authoritatively, "+
+				"status=%s error=%s",
+			ns, resp.Status, resp.Error,
+		)
+
+		hasRecords := len(resp.Records["A"]) > 0 ||
+			len(resp.Records["CNAME"]) > 0
+		assert.True(t, hasRecords,
+			"NS %s should return records for www.google.com",
+			ns,
+		)
+	}
+}
+
+func TestFindAuthoritativeNameservers_IsIterative(
+	t *testing.T,
+) {
+	// Verify that resolution works for well-known domains,
+	// proving we trace from root rather than relying on a
+	// system stub resolver that might not be configured.
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	// Resolve a well-known domain to prove root->TLD->domain
+	// tracing works.
+	nameservers, err := r.FindAuthoritativeNameservers(
+		ctx, "example.com",
+	)
+	require.NoError(t, err)
+	require.NotEmpty(t, nameservers)
+
+	t.Logf("example.com NS: %v", nameservers)
+}
+
 // ----------------------------------------------------------------
 // QueryNameserver tests
 // ----------------------------------------------------------------
@@ -217,6 +339,28 @@ func TestQueryNameserver_BasicA(t *testing.T) {
 	)
 }
 
+func TestQueryNameserver_MultipleA(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+	ns := findOneNSForDomain(t, r, ctx, testDomain)
+
+	resp, err := r.QueryNameserver(ctx, ns, testHostMultiA)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+	assert.Equal(t, resolver.StatusOK, resp.Status)
+
+	aRecords := resp.Records["A"]
+	require.Len(
+		t, aRecords, 2,
+		"multi.dns should have exactly 2 A records",
+	)
+
+	sort.Strings(aRecords)
+	assert.Equal(t, []string{"192.0.2.1", "192.0.2.2"}, aRecords)
+}
+
 func TestQueryNameserver_AAAA(t *testing.T) {
 	t.Parallel()
 
@@ -242,6 +386,44 @@ func TestQueryNameserver_AAAA(t *testing.T) {
 	}
 }
 
+func TestQueryNameserver_DualStack(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+	ns := findOneNSForDomain(t, r, ctx, testDomain)
+
+	resp, err := r.QueryNameserver(ctx, ns, testHostDualStack)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+	assert.Equal(t, resolver.StatusOK, resp.Status)
+
+	assert.Contains(t, resp.Records["A"], "192.0.2.1")
+	assert.Contains(t, resp.Records["AAAA"], "2001:db8::1")
+}
+
+func TestQueryNameserver_CNAME(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+	ns := findOneNSForDomain(t, r, ctx, testDomain)
+
+	resp, err := r.QueryNameserver(ctx, ns, testHostCNAME)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+	assert.Equal(t, resolver.StatusOK, resp.Status)
+
+	cnameRecords := resp.Records["CNAME"]
+	require.NotEmpty(
+		t, cnameRecords,
+		"cname.dns should have CNAME records",
+	)
+	assert.Contains(
+		t, cnameRecords, "cname-target.dns.sneak.cloud.",
+	)
+}
+
 func TestQueryNameserver_MX(t *testing.T) {
 	t.Parallel()
 
@@ -389,6 +571,116 @@ func TestQueryNameserver_TrailingDotHandling(t *testing.T) {
 	assert.Equal(t, resp1.Status, resp2.Status)
 }
 
+func TestQueryNameserver_NSRecordsForZoneApex(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+	ns := findOneNSForDomain(t, r, ctx, "cloudflare.com")
+
+	// Querying a zone apex should return NS records.
+	resp, err := r.QueryNameserver(
+		ctx, ns, "cloudflare.com",
+	)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+	assert.Equal(t, resolver.StatusOK, resp.Status)
+
+	nsRecords := resp.Records["NS"]
+	require.NotEmpty(t, nsRecords,
+		"zone apex should have NS records",
+	)
+
+	hasCloudflare := false
+
+	for _, nsRecord := range nsRecords {
+		if strings.Contains(nsRecord, "cloudflare") {
+			hasCloudflare = true
+
+			break
+		}
+	}
+
+	assert.True(t, hasCloudflare,
+		"NS records should include cloudflare, got: %v",
+		nsRecords,
+	)
+}
+
+func TestQueryNameserver_NoNSRecordsForLeafHostname(
+	t *testing.T,
+) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+	ns := findOneNSForDomain(t, r, ctx, "google.com")
+
+	// A leaf hostname (not a zone cut) has no NS records.
+	resp, err := r.QueryNameserver(
+		ctx, ns, "www.google.com",
+	)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+
+	assert.Empty(t, resp.Records["NS"],
+		"leaf hostname should not have NS records, got: %v",
+		resp.Records["NS"],
+	)
+}
+
+func TestQueryNameserver_LameNameserver(t *testing.T) {
+	// Querying a nameserver that does not serve a zone should
+	// return a non-ok status, not silently return empty results
+	// with status "ok". a.iana-servers.net serves example.com,
+	// not google.com.
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	resp, err := r.QueryNameserver(
+		ctx, "a.iana-servers.net.", "www.google.com",
+	)
+	require.NoError(t, err, "should not return Go-level error")
+	require.NotNil(t, resp)
+
+	assert.NotEqual(
+		t, resolver.StatusOK, resp.Status,
+		"lame NS should not return status ok; got status=%s "+
+			"records=%v",
+		resp.Status, resp.Records,
+	)
+}
+
+// ----------------------------------------------------------------
+// QueryNameserverIP tests
+// ----------------------------------------------------------------
+
+func TestQueryNameserverIP_BasicA(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	// a.iana-servers.net (199.43.135.53) is authoritative for
+	// example.com; query it directly by IP.
+	resp, err := r.QueryNameserverIP(
+		ctx, "a.iana-servers.net.", "199.43.135.53",
+		"example.com",
+	)
+	require.NoError(t, err)
+	require.NotNil(t, resp)
+
+	assert.Equal(t, resolver.StatusOK, resp.Status)
+	assert.Equal(t, "a.iana-servers.net.", resp.Nameserver)
+	assert.NotEmpty(t, resp.Records["A"],
+		"example.com should have A records",
+	)
+}
+
 // ----------------------------------------------------------------
 // QueryAllNameservers tests
 // ----------------------------------------------------------------
@@ -431,6 +723,39 @@ func TestQueryAllNameservers_AllReturnOK(t *testing.T) {
 	}
 }
 
+func TestQueryAllNameservers_Consistent(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	results, err := r.QueryAllNameservers(ctx, testHostBasic)
+	require.NoError(t, err)
+	require.NotEmpty(t, results)
+
+	// All NSes should return the same A records for a
+	// well-configured hostname.
+	var referenceRecords map[string][]string
+
+	for ns, resp := range results {
+		require.Equal(
+			t, resolver.StatusOK, resp.Status,
+			"NS %s should return OK status", ns,
+		)
+
+		if referenceRecords == nil {
+			referenceRecords = resp.Records
+
+			continue
+		}
+
+		assert.Equal(
+			t, referenceRecords["A"], resp.Records["A"],
+			"NS %s A records should match", ns,
+		)
+	}
+}
+
 func TestQueryAllNameservers_NXDomainFromAllNS(
 	t *testing.T,
 ) {
@@ -525,6 +850,80 @@ func TestResolveIPAddresses_ReturnsIPs(t *testing.T) {
 	}
 }
 
+func TestResolveIPAddresses_BasicA(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	ips, err := r.ResolveIPAddresses(ctx, testHostBasic)
+	require.NoError(t, err)
+	require.NotEmpty(t, ips)
+	assert.Contains(t, ips, "192.0.2.1")
+}
+
+func TestResolveIPAddresses_MultipleA(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	ips, err := r.ResolveIPAddresses(ctx, testHostMultiA)
+	require.NoError(t, err)
+
+	sort.Strings(ips)
+	assert.Contains(t, ips, "192.0.2.1")
+	assert.Contains(t, ips, "192.0.2.2")
+}
+
+func TestResolveIPAddresses_IPv6Only(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	ips, err := r.ResolveIPAddresses(ctx, testHostIPv6)
+	require.NoError(t, err)
+	require.NotEmpty(t, ips)
+	assert.Contains(t, ips, "2001:db8::1")
+
+	// Should not contain any IPv4
+	for _, ip := range ips {
+		parsed := net.ParseIP(ip)
+		require.NotNil(t, parsed, "should be valid IP: %s", ip)
+		assert.Nil(
+			t, parsed.To4(),
+			"ipv6-only host should not return IPv4: %s", ip,
+		)
+	}
+}
+
+func TestResolveIPAddresses_DualStack(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	ips, err := r.ResolveIPAddresses(ctx, testHostDualStack)
+	require.NoError(t, err)
+
+	assert.Contains(t, ips, "192.0.2.1")
+	assert.Contains(t, ips, "2001:db8::1")
+}
+
+func TestResolveIPAddresses_FollowsCNAME(t *testing.T) {
+	t.Parallel()
+
+	r := newTestResolver(t)
+	ctx := testContext(t)
+
+	// www.github.com is a long-standing CNAME to github.com;
+	// resolution must follow the chain to A records.
+	ips, err := r.ResolveIPAddresses(ctx, "www.github.com")
+	require.NoError(t, err)
+	require.NotEmpty(t, ips)
+}
+
 func TestResolveIPAddresses_Deduplicated(t *testing.T) {
 	t.Parallel()
 
@@ -622,42 +1021,6 @@ func TestQueryAllNameservers_ContextCanceled(t *testing.T) {
 	assert.Error(t, err)
 }
 
-// ----------------------------------------------------------------
-// Unreachable nameserver tests
-// ----------------------------------------------------------------
-
-func TestQueryNameserverIP_UnreachableServer(t *testing.T) {
-	t.Parallel()
-
-	r := newTestResolver(t)
-
-	ctx, cancel := context.WithTimeout(
-		context.Background(), 10*time.Second,
-	)
-	t.Cleanup(cancel)
-
-	// 192.0.2.1 is an RFC 5737 documentation address: no
-	// nameserver can exist there. Depending on the network
-	// path the queries either time out (silent drop) or fail
-	// fast (ICMP unreachable), so accept any non-OK status;
-	// the resolver must return a classified response with no
-	// records rather than an error or a hang.
-	resp, err := r.QueryNameserverIP(
-		ctx, "unreachable.test.", "192.0.2.1",
-		"example.com",
-	)
-	require.NoError(t, err)
-
-	assert.NotEqual(t, resolver.StatusOK, resp.Status)
-
-	totalRecords := 0
-	for _, values := range resp.Records {
-		totalRecords += len(values)
-	}
-
-	assert.Zero(t, totalRecords)
-}
-
 func TestResolveIPAddresses_ContextCanceled(t *testing.T) {
 	t.Parallel()
 

internal/state/state_test.go

@@ -13,16 +13,6 @@ import (
 
 const testHostname = "www.example.com"
 
-// Shared fixture values used across tests.
-const (
-	testNS1     = "ns1.example.com."
-	testNS2     = "ns2.example.com."
-	testAltNS1  = "ns1.test.com."
-	testIPv4    = "93.184.216.34"
-	testIP      = "1.2.3.4"
-	statusError = "error"
-)
-
 // populateState fills a State with representative test data across all categories.
 func populateState(t *testing.T, s *state.State) {
 	t.Helper()
@@ -30,7 +20,7 @@ func populateState(t *testing.T, s *state.State) {
 	now := time.Now().UTC().Truncate(time.Second)
 
 	s.SetDomainState("example.com", &state.DomainState{
-		Nameservers: []string{testNS1, testNS2},
+		Nameservers: []string{"ns1.example.com.", "ns2.example.com."},
 		LastChecked: now,
 	})
 
@@ -41,17 +31,17 @@ func populateState(t *testing.T, s *state.State) {
 
 	s.SetHostnameState(testHostname, &state.HostnameState{
 		RecordsByNameserver: map[string]*state.NameserverRecordState{
-			testNS1: {
+			"ns1.example.com.": {
 				Records: map[string][]string{
-					"A":    {testIPv4},
+					"A":    {"93.184.216.34"},
 					"AAAA": {"2606:2800:220:1:248:1893:25c8:1946"},
 				},
 				Status:      "ok",
 				LastChecked: now,
 			},
-			testNS2: {
+			"ns2.example.com.": {
 				Records: map[string][]string{
-					"A": {testIPv4},
+					"A": {"93.184.216.34"},
 				},
 				Status:      "ok",
 				LastChecked: now,
@@ -162,13 +152,13 @@ func TestSaveLoadRoundTrip_Hostnames(t *testing.T) {
 func verifyNS1Records(t *testing.T, hn *state.HostnameState) {
 	t.Helper()
 
-	ns1, ok := hn.RecordsByNameserver[testNS1]
+	ns1, ok := hn.RecordsByNameserver["ns1.example.com."]
 	if !ok {
 		t.Fatal("missing nameserver ns1.example.com.")
 	}
 
 	aRecords := ns1.Records["A"]
-	if len(aRecords) != 1 || aRecords[0] != testIPv4 {
+	if len(aRecords) != 1 || aRecords[0] != "93.184.216.34" {
 		t.Errorf("ns1 A records: got %v", aRecords)
 	}
 
@@ -223,8 +213,7 @@ func TestSaveLoadRoundTrip_Ports(t *testing.T) {
 	}
 }
 
-// TestSaveLoadRoundTrip_Certificates verifies certificate data
+// TestSaveLoadRoundTrip_Certificates verifies certificate data survives a save/load cycle.
-// survives a save/load cycle.
 func TestSaveLoadRoundTrip_Certificates(t *testing.T) {
 	t.Parallel()
 
@@ -664,7 +653,7 @@ func TestDomainState_GetSet(t *testing.T) {
 
 	now := time.Now().UTC().Truncate(time.Second)
 	ds := &state.DomainState{
-		Nameservers: []string{testAltNS1},
+		Nameservers: []string{"ns1.test.com."},
 		LastChecked: now,
 	}
 
@@ -675,7 +664,7 @@ func TestDomainState_GetSet(t *testing.T) {
 		t.Fatal("expected true for existing domain")
 	}
 
-	if len(got.Nameservers) != 1 || got.Nameservers[0] != testAltNS1 {
+	if len(got.Nameservers) != 1 || got.Nameservers[0] != "ns1.test.com." {
 		t.Errorf("nameservers: got %v", got.Nameservers)
 	}
 
@@ -685,7 +674,7 @@ func TestDomainState_GetSet(t *testing.T) {
 
 	// Overwrite.
 	ds2 := &state.DomainState{
-		Nameservers: []string{testAltNS1, "ns2.test.com."},
+		Nameservers: []string{"ns1.test.com.", "ns2.test.com."},
 		LastChecked: now.Add(time.Hour),
 	}
 
@@ -715,8 +704,8 @@ func TestHostnameState_GetSet(t *testing.T) {
 	now := time.Now().UTC().Truncate(time.Second)
 	hs := &state.HostnameState{
 		RecordsByNameserver: map[string]*state.NameserverRecordState{
-			testNS1: {
+			"ns1.example.com.": {
-				Records:     map[string][]string{"A": {testIP}},
+				Records:     map[string][]string{"A": {"1.2.3.4"}},
 				Status:      "ok",
 				LastChecked: now,
 			},
@@ -731,7 +720,7 @@ func TestHostnameState_GetSet(t *testing.T) {
 		t.Fatal("expected true for existing hostname")
 	}
 
-	nsState, ok := got.RecordsByNameserver[testNS1]
+	nsState, ok := got.RecordsByNameserver["ns1.example.com."]
 	if !ok {
 		t.Fatal("missing nameserver entry")
 	}
@@ -741,7 +730,7 @@ func TestHostnameState_GetSet(t *testing.T) {
 	}
 
 	aRecords := nsState.Records["A"]
-	if len(aRecords) != 1 || aRecords[0] != testIP {
+	if len(aRecords) != 1 || aRecords[0] != "1.2.3.4" {
 		t.Errorf("A records: got %v", aRecords)
 	}
 }
@@ -880,7 +869,7 @@ func TestCertificateState_ErrorField(t *testing.T) {
 
 	now := time.Now().UTC().Truncate(time.Second)
 	cs := &state.CertificateState{
-		Status:      statusError,
+		Status:      "error",
 		Error:       "connection refused",
 		LastChecked: now,
 	}
@@ -904,8 +893,8 @@ func TestCertificateState_ErrorField(t *testing.T) {
 		t.Fatal("missing certificate after load")
 	}
 
-	if got.Status != statusError {
+	if got.Status != "error" {
-		t.Errorf("status: got %q, want %q", got.Status, statusError)
+		t.Errorf("status: got %q, want %q", got.Status, "error")
 	}
 
 	if got.Error != "connection refused" {
@@ -923,9 +912,9 @@ func TestHostnameState_ErrorField(t *testing.T) {
 	now := time.Now().UTC().Truncate(time.Second)
 	hs := &state.HostnameState{
 		RecordsByNameserver: map[string]*state.NameserverRecordState{
-			testNS1: {
+			"ns1.example.com.": {
 				Records:     nil,
-				Status:      statusError,
+				Status:      "error",
 				Error:       "SERVFAIL",
 				LastChecked: now,
 			},
@@ -952,9 +941,9 @@ func TestHostnameState_ErrorField(t *testing.T) {
 		t.Fatal("missing hostname after load")
 	}
 
-	nsState := got.RecordsByNameserver[testNS1]
+	nsState := got.RecordsByNameserver["ns1.example.com."]
-	if nsState.Status != statusError {
+	if nsState.Status != "error" {
-		t.Errorf("status: got %q, want %q", nsState.Status, statusError)
+		t.Errorf("status: got %q, want %q", nsState.Status, "error")
 	}
 
 	if nsState.Error != "SERVFAIL" {
@@ -1073,8 +1062,7 @@ func TestConcurrentGetSet(t *testing.T) {
 	wg.Wait()
 }
 
-// runConcurrentOps performs a series of get/set/delete
+// runConcurrentOps performs a series of get/set/delete operations for concurrency testing.
-// operations for concurrency testing.
 func runConcurrentOps(s *state.State, key string, now time.Time) {
 	const iterations = 50
 
@@ -1097,7 +1085,7 @@ func runConcurrentOps(s *state.State, key string, now time.Time) {
 		s.SetHostnameState(key+".example.com", &state.HostnameState{
 			RecordsByNameserver: map[string]*state.NameserverRecordState{
 				"ns1.test.": {
-					Records:     map[string][]string{"A": {testIP}},
+					Records:     map[string][]string{"A": {"1.2.3.4"}},
 					Status:      "ok",
 					LastChecked: now,
 				},

internal/watcher/watcher.go

@@ -26,12 +26,6 @@ const tlsPort = 443
 // hoursPerDay converts days to hours for duration calculations.
 const hoursPerDay = 24
 
-// Status values recorded for nameserver and certificate checks.
-const (
-	statusOK    = "ok"
-	statusError = "error"
-)
-
 // Params contains dependencies for Watcher.
 type Params struct {
 	fx.In
@@ -350,7 +344,7 @@ func buildHostnameState(
 	for ns, recs := range records {
 		hs.RecordsByNameserver[ns] = &state.NameserverRecordState{
 			Records:     recs,
-			Status:      statusOK,
+			Status:      "ok",
 			LastChecked: now,
 		}
 	}
@@ -408,7 +402,7 @@ func (w *Watcher) detectNSDisappearances(
 	current map[string]map[string][]string,
 ) {
 	for ns, prevNS := range prev.RecordsByNameserver {
-		if _, ok := current[ns]; ok || prevNS.Status != statusOK {
+		if _, ok := current[ns]; ok || prevNS.Status != "ok" {
 			continue
 		}
 
@@ -427,7 +421,7 @@ func (w *Watcher) detectNSDisappearances(
 
 	for ns := range current {
 		prevNS, ok := prev.RecordsByNameserver[ns]
-		if !ok || prevNS.Status != statusError {
+		if !ok || prevNS.Status != "error" {
 			continue
 		}
 
@@ -711,7 +705,7 @@ func (w *Watcher) handleTLSError(
 	now time.Time,
 	err error,
 ) {
-	if hasPrev && !w.firstRun && prev.Status == statusOK {
+	if hasPrev && !w.firstRun && prev.Status == "ok" {
 		msg := fmt.Sprintf(
 			"Host: %s\nIP: %s\nError: %s",
 			hostname, ip, err,
@@ -727,7 +721,7 @@ func (w *Watcher) handleTLSError(
 
 	w.state.SetCertificateState(
 		certKey, &state.CertificateState{
-			Status:      statusError,
+			Status:      "error",
 			Error:       err.Error(),
 			LastChecked: now,
 		},
@@ -754,7 +748,7 @@ func (w *Watcher) handleTLSSuccess(
 			Issuer:                  cert.Issuer,
 			NotAfter:                cert.NotAfter,
 			SubjectAlternativeNames: cert.SubjectAlternativeNames,
-			Status:                  statusOK,
+			Status:                  "ok",
 			LastChecked:             now,
 		},
 	)
@@ -766,7 +760,7 @@ func (w *Watcher) detectTLSChanges(
 	prev *state.CertificateState,
 	cert *tlscheck.CertificateInfo,
 ) {
-	if prev.Status == statusError {
+	if prev.Status == "error" {
 		msg := fmt.Sprintf(
 			"Host: %s\nIP: %s\nTLS recovered",
 			hostname, ip,

script/bootstrap

@@ -9,9 +9,9 @@ set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
-# Pinned versions, 2026-08-07 (same pins as the Dockerfile)
+# Pinned versions, 2026-07-07 (same pins as the Dockerfile)
-# golangci-lint v2.12.2
+# golangci-lint v2.10.1
-GOLANGCI_LINT_REF="github.com/golangci/golangci-lint/v2/cmd/golangci-lint@c0d3ddc9cf3faa61a4e378e879ece580256d76e5"
+GOLANGCI_LINT_REF="github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee"
 # goimports v0.42.0
 GOIMPORTS_REF="golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0"