fix: use proper YAML parsing for no-db mode detection (bd-r6k2)

Replace fragile strings.Contains("no-db: true") with proper YAML parsing
to avoid false matches in comments or nested keys.

Changes:
- Add NoDb field to localConfig struct
- Add isNoDbModeConfigured() helper function
- Update main.go and doctor.go to use the helper
- Add 8 test cases for isNoDbModeConfigured

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/autoimport.go

@@ -143,10 +143,28 @@ func checkGitForIssues() (int, string, string) {
 	return 0, "", ""
 }
 
-// localConfig represents the subset of config.yaml we need for auto-import.
+// localConfig represents the subset of config.yaml we need for auto-import and no-db detection.
 // Using proper YAML parsing handles edge cases like comments, indentation, and special characters.
 type localConfig struct {
 	SyncBranch string `yaml:"sync-branch"`
+	NoDb       bool   `yaml:"no-db"`
+}
+
+// isNoDbModeConfigured checks if no-db: true is set in config.yaml.
+// Uses proper YAML parsing to avoid false matches in comments or nested keys.
+func isNoDbModeConfigured(beadsDir string) bool {
+	configPath := filepath.Join(beadsDir, "config.yaml")
+	data, err := os.ReadFile(configPath) // #nosec G304 - config file path from beadsDir
+	if err != nil {
+		return false
+	}
+
+	var cfg localConfig
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return false
+	}
+
+	return cfg.NoDb
 }
 
 // getLocalSyncBranch reads sync-branch from the local config.yaml file.

cmd/bd/autoimport_test.go

@@ -299,6 +299,85 @@ func TestBoolToFlag(t *testing.T) {
 	}
 }
 
+func TestIsNoDbModeConfigured(t *testing.T) {
+	tests := []struct {
+		name       string
+		configYAML string
+		createFile bool
+		want       bool
+	}{
+		{
+			name:       "no config.yaml exists",
+			createFile: false,
+			want:       false,
+		},
+		{
+			name:       "config.yaml without no-db key",
+			configYAML: "issue-prefix: test\nauthor: testuser\n",
+			createFile: true,
+			want:       false,
+		},
+		{
+			name:       "no-db: true",
+			configYAML: "no-db: true\n",
+			createFile: true,
+			want:       true,
+		},
+		{
+			name:       "no-db: false",
+			configYAML: "no-db: false\n",
+			createFile: true,
+			want:       false,
+		},
+		{
+			name:       "no-db in comment should not match",
+			configYAML: "# no-db: true\nissue-prefix: test\n",
+			createFile: true,
+			want:       false,
+		},
+		{
+			name:       "no-db nested under section should not match",
+			configYAML: "settings:\n  no-db: true\n",
+			createFile: true,
+			want:       false,
+		},
+		{
+			name:       "no-db with other config",
+			configYAML: "issue-prefix: bd\nno-db: true\nauthor: steve\n",
+			createFile: true,
+			want:       true,
+		},
+		{
+			name:       "empty file",
+			configYAML: "",
+			createFile: true,
+			want:       false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir := t.TempDir()
+			beadsDir := filepath.Join(tmpDir, ".beads")
+			if err := os.MkdirAll(beadsDir, 0755); err != nil {
+				t.Fatalf("Failed to create beads dir: %v", err)
+			}
+
+			if tt.createFile {
+				configPath := filepath.Join(beadsDir, "config.yaml")
+				if err := os.WriteFile(configPath, []byte(tt.configYAML), 0644); err != nil {
+					t.Fatalf("Failed to write config.yaml: %v", err)
+				}
+			}
+
+			got := isNoDbModeConfigured(beadsDir)
+			if got != tt.want {
+				t.Errorf("isNoDbModeConfigured() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
 func TestGetLocalSyncBranch(t *testing.T) {
 	tests := []struct {
 		name        string

cmd/bd/doctor.go

@@ -854,16 +854,8 @@ func checkDatabaseVersion(path string) doctorCheck {
 
 		if jsonlPath != "" {
 			// JSONL exists but no database - check if this is no-db mode or fresh clone
-			// Check config.yaml for no-db: true
-			configPath := filepath.Join(beadsDir, "config.yaml")
-			isNoDbMode := false
-			// #nosec G304 -- configPath is constructed from beadsDir which is in .beads/
-			if configData, err := os.ReadFile(configPath); err == nil {
-				// Simple check for no-db: true in config.yaml
-				isNoDbMode = strings.Contains(string(configData), "no-db: true")
-			}
-
-			if isNoDbMode {
+			// Use proper YAML parsing to detect no-db mode (bd-r6k2)
+			if isNoDbModeConfigured(beadsDir) {
 				return doctorCheck{
 					Name:    "Database",
 					Status:  statusOK,

cmd/bd/main.go

@@ -296,7 +296,6 @@ var rootCmd = &cobra.Command{
 				beadsDir := beads.FindBeadsDir()
 				if beadsDir != "" {
 					jsonlPath := filepath.Join(beadsDir, "issues.jsonl")
-					configPath := filepath.Join(beadsDir, "config.yaml")
 
 					// Check if JSONL exists and config.yaml has no-db: true
 					jsonlExists := false
@@ -304,11 +303,8 @@ var rootCmd = &cobra.Command{
 						jsonlExists = true
 					}
 
-					isNoDbMode := false
-					// configPath is safe: constructed from filepath.Join(beadsDir, hardcoded name)
-					if configData, err := os.ReadFile(configPath); err == nil { //nolint:gosec
-						isNoDbMode = strings.Contains(string(configData), "no-db: true")
-					}
+					// Use proper YAML parsing to detect no-db mode (bd-r6k2)
+					isNoDbMode := isNoDbModeConfigured(beadsDir)
 
 					// If JSONL-only mode is configured, auto-enable it
 					if jsonlExists && isNoDbMode {