Update golangci-lint to v2.12.2 with canonical config (#187)

Bumps golangci-lint from v2.10.1 to v2.12.2 everywhere it is pinned and installs the canonical `.golangci.yml`, then fixes every finding the new linter surfaces so `make check` is green.

## Version pins

- `Dockerfile` lint stage: `golangci/golangci-lint:v2.12.2` (Debian-based), tag plus digest pin
- `script/bootstrap`: `GOLANGCI_LINT_VERSION=2.12.2` with updated `linux-amd64`/`linux-arm64` release-archive sha256 pins

## Config

`.golangci.yml` replaced with the canonical config. Material change: the old file declared `version: "2"` but kept settings under the legacy top-level `linters-settings` key, which golangci-lint v2 ignores — so the intended thresholds (`lll` 88, `funlen` 80/50, `cyclop` 15, `dupl` 100) were not being applied. The canonical file moves them under `linters.settings` and drops `issues.exclude-use-default`.

## Lint fixes (216 findings)

- `lll` (96): wrapped lines to the 88-column limit
- `noctx` (46): `httptest.NewRequestWithContext` with `t.Context()` throughout the tests
- `goconst` (24): shared constants for template/JSON keys in `internal/handlers` and repeated test literals
- `gosec` (23): app-page redirects now go through a `redirectToApp` helper that path-escapes the app ID (G710 open redirect); `http.ServeFile` of the internally derived deployment log path annotated like the adjacent `os.Stat` (G703)
- `dupl` (22): extracted a generic `findAllByAppID` in `internal/models`, a `deleteAppResource` helper in `internal/handlers`, a shared `parsePush` in `internal/service/webhook`, and table-driven/helper-based dedup in tests
- `nolintlint` (5): removed `//nolint:funlen` directives made obsolete by the new limits (plus one more that became obsolete after refactoring)
- `nilerr` (3, surfaced during fixing): resource-delete lookups now propagate the find error to the caller

No behavior changes intended; all tests pass and `make check` is green.

Note: golangci-lint v2.12 warns that `gomodguard` is deprecated in favor of `gomodguard_v2` — a future canonical-config update should address this centrally.
Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #187
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/middleware/ratelimit_test.go

@@ -30,13 +30,15 @@ func TestLoginRateLimitAllowsUpToBurst(t *testing.T) {
 
 	mw := newTestMiddleware(t)
 
-	handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		w.WriteHeader(http.StatusOK)
-	}))
+	handler := mw.LoginRateLimit()(http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		},
+	))
 
 	// First 5 requests should succeed (burst)
 	for i := range 5 {
-		req := httptest.NewRequest(http.MethodPost, "/login", nil)
+		req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
 		req.RemoteAddr = "192.168.1.1:12345"
 		rec := httptest.NewRecorder()
 		handler.ServeHTTP(rec, req)
@@ -44,11 +46,12 @@ func TestLoginRateLimitAllowsUpToBurst(t *testing.T) {
 	}
 
 	// 6th request should be rate limited
-	req := httptest.NewRequest(http.MethodPost, "/login", nil)
+	req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
 	req.RemoteAddr = "192.168.1.1:12345"
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
-	assert.Equal(t, http.StatusTooManyRequests, rec.Code, "6th request should be rate limited")
+	assert.Equal(t, http.StatusTooManyRequests, rec.Code,
+		"6th request should be rate limited")
 }
 
 //nolint:paralleltest // mutates global loginLimiter
@@ -57,27 +60,29 @@ func TestLoginRateLimitIsolatesIPs(t *testing.T) {
 
 	mw := newTestMiddleware(t)
 
-	handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		w.WriteHeader(http.StatusOK)
-	}))
+	handler := mw.LoginRateLimit()(http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		},
+	))
 
 	// Exhaust IP1's budget
 	for range 5 {
-		req := httptest.NewRequest(http.MethodPost, "/login", nil)
-		req.RemoteAddr = "10.0.0.1:1234"
+		req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
+		req.RemoteAddr = testProxyAddr
 		rec := httptest.NewRecorder()
 		handler.ServeHTTP(rec, req)
 	}
 
 	// IP1 should be blocked
-	req := httptest.NewRequest(http.MethodPost, "/login", nil)
-	req.RemoteAddr = "10.0.0.1:1234"
+	req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
+	req.RemoteAddr = testProxyAddr
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
 	assert.Equal(t, http.StatusTooManyRequests, rec.Code)
 
 	// IP2 should still work
-	req2 := httptest.NewRequest(http.MethodPost, "/login", nil)
+	req2 := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
 	req2.RemoteAddr = "10.0.0.2:1234"
 	rec2 := httptest.NewRecorder()
 	handler.ServeHTTP(rec2, req2)
@@ -90,25 +95,28 @@ func TestLoginRateLimitReturns429Body(t *testing.T) {
 
 	mw := newTestMiddleware(t)
 
-	handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		w.WriteHeader(http.StatusOK)
-	}))
+	handler := mw.LoginRateLimit()(http.HandlerFunc(
+		func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		},
+	))
 
 	// Exhaust burst
 	for range 5 {
-		req := httptest.NewRequest(http.MethodPost, "/login", nil)
+		req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
 		req.RemoteAddr = "172.16.0.1:5555"
 		rec := httptest.NewRecorder()
 		handler.ServeHTTP(rec, req)
 	}
 
-	req := httptest.NewRequest(http.MethodPost, "/login", nil)
+	req := httptest.NewRequestWithContext(t.Context(), http.MethodPost, "/login", nil)
 	req.RemoteAddr = "172.16.0.1:5555"
 	rec := httptest.NewRecorder()
 	handler.ServeHTTP(rec, req)
 	assert.Equal(t, http.StatusTooManyRequests, rec.Code)
 	assert.Contains(t, rec.Body.String(), "Too Many Requests")
-	assert.NotEmpty(t, rec.Header().Get("Retry-After"), "should include Retry-After header")
+	assert.NotEmpty(t, rec.Header().Get("Retry-After"),
+		"should include Retry-After header")
 }
 
 func TestIPLimiterEvictsStaleEntries(t *testing.T) {