Update golangci-lint to v2.12.2 with canonical config (#62)

Updates golangci-lint to v2.12.2 everywhere it is pinned and installs the canonical `.golangci.yml`, then remediates every finding the new linter/config surfaces so `make check` is green.

## Version bump

- `Dockerfile` lint stage: `golangci/golangci-lint:v2.11.3-alpine` -> `v2.12.2-alpine` (digest-pinned, date comment updated)
- `Makefile` `deps` target: `go install` moved from the old v1 module path at `@latest` to the pinned `github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2`
- `.golangci.yml` replaced with the canonical config (v2 schema; settings under `linters.settings` so the thresholds actually apply; `default: all` with the standard six disables)
- `script/bootstrap` installs golangci-lint via the system package manager and carries no version pin, so it is unchanged
- CI (`.gitea/workflows/check.yml`) only runs `script/cibuild`, so it needed no change

## Lint remediation

The canonical config surfaced ~3,300 findings across 56k lines. All are fixed, behavior-preserving; incorporates and supersedes the per-package mechanical passes already merged to `main` (refs #61). Highlights:

- `err113`: dynamic errors replaced with package sentinels + `%w` wrapping; comparisons via `errors.Is`
- `goprintffuncname`: printf-style helpers renamed with an `f` suffix (`ui.Writer` message methods, `cli.ReportErrorf`, `database.Fatalf`) and all call sites updated
- `revive` stutter renames: `blob.Handler`, `blob.WithReader`, `blob.ChunkPosition`, `storage.URL`, `storage.Info`; missing doc comments added
- `contextcheck`/`noctx`: `context.Context` threaded through `blob.Packer` and the scanner call sites; context-aware `exec`/`sql` variants
- `funlen`/`cyclop`/`gocognit`/`dupl`: oversized and duplicated functions split into focused helpers (production and test code)
- tests: `t.Parallel()` added where safe (global logger init kept in the serial phase for `-race`), `t.TempDir()`/`t.Helper()` adopted, several suites converted to external test packages
- `gosec`: bounded integer conversions, `ReadHeaderTimeout` on the test HTTP server; remaining warnings suppressed per-site with justifications
- remaining `nolint` directives are rare, targeted, and each carries a reason (e.g. `nilnil` not-found contract in the repository layer, fx module globals, on-disk snake_case struct tags)
- removed the deprecated `log.LogOptions` alias (callers migrated to `log.Options`)

`make check` (tests with `-race`, lint, fmt-check) passes.

Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #62
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/config/config_test.go

@@ -1,4 +1,4 @@
-package config
+package config //nolint:testpackage // exercises unexported extractAgeSecretKey
 
 import (
 	"os"
@@ -7,9 +7,12 @@ import (
 )
 
 const (
-	TEST_SNEAK_AGE_PUBLIC_KEY        = "age1278m9q7dp3chsh2dcy82qk27v047zywyvtxwnj4cvt0z65jw6a7q5dqhfj"
-	TEST_INTEGRATION_AGE_PUBLIC_KEY  = "age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg"
-	TEST_INTEGRATION_AGE_PRIVATE_KEY = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
+	testSneakAgePublicKey = "age1278m9q7dp3chsh2dcy82qk27v047zywyvt" +
+		"xwnj4cvt0z65jw6a7q5dqhfj"
+	testIntegrationAgePublicKey = "age1ezrjmfpwsc95svdg0y54mums3zevgzu" +
+		"0x0ecq2f7tp8a05gl0sjq9q9wjg"
+	testIntegrationAgePrivateKey = "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GX" +
+		"VEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5"
 )
 
 func TestMain(m *testing.M) {
@@ -25,8 +28,11 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
-// TestConfigLoad ensures the config package can be imported and basic functionality works
+// TestConfigLoad ensures the config package can be imported and basic
+// functionality works.
 func TestConfigLoad(t *testing.T) {
+	t.Parallel()
+
 	// Use the test config file
 	configPath := os.Getenv("VAULTIK_CONFIG")
 	if configPath == "" {
@@ -44,8 +50,9 @@ func TestConfigLoad(t *testing.T) {
 		t.Errorf("Expected 2 age recipients, got %d", len(cfg.AgeRecipients))
 	}
 
-	if cfg.AgeRecipients[0] != TEST_SNEAK_AGE_PUBLIC_KEY {
-		t.Errorf("Expected first age recipient to be %s, got '%s'", TEST_SNEAK_AGE_PUBLIC_KEY, cfg.AgeRecipients[0])
+	if cfg.AgeRecipients[0] != testSneakAgePublicKey {
+		t.Errorf("Expected first age recipient to be %s, got '%s'",
+			testSneakAgePublicKey, cfg.AgeRecipients[0])
 	}
 
 	if len(cfg.Snapshots) != 1 {
@@ -62,11 +69,13 @@ func TestConfigLoad(t *testing.T) {
 	}
 
 	if testSnap.Paths[0] != "/tmp/vaultik-test-source" {
-		t.Errorf("Expected first path to be '/tmp/vaultik-test-source', got '%s'", testSnap.Paths[0])
+		t.Errorf("Expected first path to be '/tmp/vaultik-test-source', got '%s'",
+			testSnap.Paths[0])
 	}
 
 	if cfg.S3.Bucket != "vaultik-test-bucket" {
-		t.Errorf("Expected S3 bucket to be 'vaultik-test-bucket', got '%s'", cfg.S3.Bucket)
+		t.Errorf("Expected S3 bucket to be 'vaultik-test-bucket', got '%s'",
+			cfg.S3.Bucket)
 	}
 
 	if cfg.Hostname != "test-host" {
@@ -76,19 +85,26 @@ func TestConfigLoad(t *testing.T) {
 
 // TestConfigFromEnv tests loading config path from environment variable
 func TestConfigFromEnv(t *testing.T) {
+	t.Parallel()
+
 	configPath := os.Getenv("VAULTIK_CONFIG")
 	if configPath == "" {
 		t.Skip("VAULTIK_CONFIG not set")
 	}
 
 	// Verify the file exists
-	if _, err := os.Stat(configPath); os.IsNotExist(err) {
-		t.Errorf("Config file does not exist at path from VAULTIK_CONFIG: %s", configPath)
+	//nolint:gosec // G703: test config path comes from the test environment
+	_, err := os.Stat(configPath)
+	if os.IsNotExist(err) {
+		t.Errorf("Config file does not exist at path from VAULTIK_CONFIG: %s",
+			configPath)
 	}
 }
 
 // TestExtractAgeSecretKey tests extraction of AGE-SECRET-KEY from various inputs
 func TestExtractAgeSecretKey(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name     string
 		input    string
@@ -96,36 +112,32 @@ func TestExtractAgeSecretKey(t *testing.T) {
 	}{
 		{
 			name:     "plain key",
-			input:    "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    testIntegrationAgePrivateKey,
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "key with trailing newline",
-			input:    "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5\n",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    testIntegrationAgePrivateKey + "\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name: "full age-keygen output",
-			input: `# created: 2025-01-14T12:00:00Z
-# public key: age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg
-AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
-`,
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input: "# created: 2025-01-14T12:00:00Z\n" +
+				"# public key: " + testIntegrationAgePublicKey + "\n" +
+				testIntegrationAgePrivateKey + "\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name: "age-keygen output with extra blank lines",
-			input: `# created: 2025-01-14T12:00:00Z
-# public key: age1ezrjmfpwsc95svdg0y54mums3zevgzu0x0ecq2f7tp8a05gl0sjq9q9wjg
-
-AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
-
-`,
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input: "# created: 2025-01-14T12:00:00Z\n" +
+				"# public key: " + testIntegrationAgePublicKey + "\n\n" +
+				testIntegrationAgePrivateKey + "\n\n",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "key with leading whitespace",
-			input:    "  AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5  ",
-			expected: "AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5",
+			input:    "  " + testIntegrationAgePrivateKey + "  ",
+			expected: testIntegrationAgePrivateKey,
 		},
 		{
 			name:     "empty input",
@@ -141,9 +153,12 @@ AGE-SECRET-KEY-19CR5YSFW59HM4TLD6GXVEDMZFTVVF7PPHKUT68TXSFPK7APHXA2QS2NJA5
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
 			result := extractAgeSecretKey(tt.input)
 			if result != tt.expected {
-				t.Errorf("extractAgeSecretKey(%q) = %q, want %q", tt.input, result, tt.expected)
+				t.Errorf("extractAgeSecretKey(%q) = %q, want %q",
+					tt.input, result, tt.expected)
 			}
 		})
 	}