fix: validate project files in FindBeadsDir (bd-420) (#424)

FindBeadsDir() now checks for actual beads project files before returning
a .beads directory. This prevents false positives when ~/.beads/ exists
only for daemon registry (registry.json).

Changes:
- Add hasBeadsProjectFiles() helper that checks for:
  - metadata.json or config.yaml (project config)
  - *.db files (excluding backups and vc.db)
  - *.jsonl files (JSONL-only mode)
- Update FindBeadsDir() to validate directories during tree search
- Add comprehensive tests for project file detection
- Update version_tracking_test.go to create project files

Fixes #420

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

Co-authored-by: Claude <noreply@anthropic.com>

cmd/bd/version_tracking_test.go

@@ -124,12 +124,18 @@ func TestTrackBdVersion_NoBeadsDir(t *testing.T) {
 }
 
 func TestTrackBdVersion_FirstRun(t *testing.T) {
-	// Create temp .beads directory
+	// Create temp .beads directory with a project file (bd-420)
+	// FindBeadsDir now requires actual project files, not just directory existence
 	tmpDir := t.TempDir()
 	beadsDir := filepath.Join(tmpDir, ".beads")
 	if err := os.MkdirAll(beadsDir, 0755); err != nil {
 		t.Fatalf("Failed to create .beads: %v", err)
 	}
+	// Create a database file so FindBeadsDir finds this directory
+	dbPath := filepath.Join(beadsDir, "beads.db")
+	if err := os.WriteFile(dbPath, []byte{}, 0644); err != nil {
+		t.Fatalf("Failed to create db file: %v", err)
+	}
 
 	// Change to temp directory
 	origWd, _ := os.Getwd()

internal/beads/beads.go

@@ -230,9 +230,45 @@ func FindDatabasePath() string {
 	return ""
 }
 
+// hasBeadsProjectFiles checks if a .beads directory contains actual project files.
+// Returns true if the directory contains any of:
+// - metadata.json or config.yaml (project configuration)
+// - Any *.db file (excluding backups and vc.db)
+// - Any *.jsonl file (JSONL-only mode or git-tracked issues)
+//
+// Returns false for directories that only contain daemon registry files (bd-420).
+// This prevents FindBeadsDir from returning ~/.beads/ which only has registry.json.
+func hasBeadsProjectFiles(beadsDir string) bool {
+	// Check for project configuration files
+	if _, err := os.Stat(filepath.Join(beadsDir, "metadata.json")); err == nil {
+		return true
+	}
+	if _, err := os.Stat(filepath.Join(beadsDir, "config.yaml")); err == nil {
+		return true
+	}
+
+	// Check for database files (excluding backups and vc.db)
+	dbMatches, _ := filepath.Glob(filepath.Join(beadsDir, "*.db"))
+	for _, match := range dbMatches {
+		baseName := filepath.Base(match)
+		if !strings.Contains(baseName, ".backup") && baseName != "vc.db" {
+			return true
+		}
+	}
+
+	// Check for JSONL files (JSONL-only mode or fresh clone)
+	jsonlMatches, _ := filepath.Glob(filepath.Join(beadsDir, "*.jsonl"))
+	if len(jsonlMatches) > 0 {
+		return true
+	}
+
+	return false
+}
+
 // FindBeadsDir finds the .beads/ directory in the current directory tree
 // Returns empty string if not found. Supports both database and JSONL-only mode.
 // Stops at the git repository root to avoid finding unrelated directories (bd-c8x).
+// Validates that the directory contains actual project files (bd-420).
 // This is useful for commands that need to detect beads projects without requiring a database.
 func FindBeadsDir() string {
 	// 1. Check BEADS_DIR environment variable (preferred)
@@ -255,8 +291,11 @@ func FindBeadsDir() string {
 	for dir := cwd; dir != "/" && dir != "."; dir = filepath.Dir(dir) {
 		beadsDir := filepath.Join(dir, ".beads")
 		if info, err := os.Stat(beadsDir); err == nil && info.IsDir() {
+			// Validate directory contains actual project files (bd-420)
+			if hasBeadsProjectFiles(beadsDir) {
 				return beadsDir
 			}
+		}
 
 		// Stop at git root to avoid finding unrelated directories (bd-c8x)
 		if gitRoot != "" && dir == gitRoot {

internal/beads/beads_test.go

@@ -282,6 +282,134 @@ func TestFindJSONLPathSkipsDeletions(t *testing.T) {
 	}
 }
 
+// TestHasBeadsProjectFiles verifies that hasBeadsProjectFiles correctly
+// distinguishes between project directories and daemon-only directories (bd-420)
+func TestHasBeadsProjectFiles(t *testing.T) {
+	tests := []struct {
+		name     string
+		files    []string
+		expected bool
+	}{
+		{
+			name:     "empty directory",
+			files:    []string{},
+			expected: false,
+		},
+		{
+			name:     "daemon registry only",
+			files:    []string{"registry.json", "registry.lock"},
+			expected: false,
+		},
+		{
+			name:     "has database",
+			files:    []string{"beads.db"},
+			expected: true,
+		},
+		{
+			name:     "has issues.jsonl",
+			files:    []string{"issues.jsonl"},
+			expected: true,
+		},
+		{
+			name:     "has metadata.json",
+			files:    []string{"metadata.json"},
+			expected: true,
+		},
+		{
+			name:     "has config.yaml",
+			files:    []string{"config.yaml"},
+			expected: true,
+		},
+		{
+			name:     "ignores backup db",
+			files:    []string{"beads.backup.db"},
+			expected: false,
+		},
+		{
+			name:     "ignores vc.db",
+			files:    []string{"vc.db"},
+			expected: false,
+		},
+		{
+			name:     "real db with backup",
+			files:    []string{"beads.db", "beads.backup.db"},
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir, err := os.MkdirTemp("", "beads-project-test-*")
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer os.RemoveAll(tmpDir)
+
+			// Create test files
+			for _, file := range tt.files {
+				path := filepath.Join(tmpDir, file)
+				if err := os.WriteFile(path, []byte("{}"), 0644); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			result := hasBeadsProjectFiles(tmpDir)
+			if result != tt.expected {
+				t.Errorf("hasBeadsProjectFiles() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}
+
+// TestFindBeadsDirSkipsDaemonRegistry verifies that FindBeadsDir skips
+// directories containing only daemon registry files (bd-420)
+func TestFindBeadsDirSkipsDaemonRegistry(t *testing.T) {
+	// Save original state
+	originalEnv := os.Getenv("BEADS_DIR")
+	originalWd, _ := os.Getwd()
+	defer func() {
+		if originalEnv != "" {
+			os.Setenv("BEADS_DIR", originalEnv)
+		} else {
+			os.Unsetenv("BEADS_DIR")
+		}
+		os.Chdir(originalWd)
+	}()
+	os.Unsetenv("BEADS_DIR")
+
+	// Create temp directory structure
+	tmpDir, err := os.MkdirTemp("", "beads-daemon-test-*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create .beads with only daemon registry files (should be skipped)
+	beadsDir := filepath.Join(tmpDir, ".beads")
+	if err := os.MkdirAll(beadsDir, 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(beadsDir, "registry.json"), []byte("[]"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Change to temp dir
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatal(err)
+	}
+
+	// Should NOT find the daemon-only directory
+	result := FindBeadsDir()
+	if result != "" {
+		// Resolve symlinks for comparison
+		resultResolved, _ := filepath.EvalSymlinks(result)
+		beadsDirResolved, _ := filepath.EvalSymlinks(beadsDir)
+		if resultResolved == beadsDirResolved {
+			t.Errorf("FindBeadsDir() should skip daemon-only directory, got %q", result)
+		}
+	}
+}
+
 func TestFindDatabasePathHomeDefault(t *testing.T) {
 	// This test verifies that if no database is found, it falls back to home directory
 	// We can't reliably test this without modifying the home directory, so we'll skip