Remove spurious collision-related code after ultrathink review

After 2 weeks of collision/stale-data fixes, reviewed all changes to identify
spurious code that is no longer needed after content-hash resolution was implemented.

**Removed:**
1. countReferences() function from collision.go (lines 274-328)
   - Was used for reference-count based collision scoring
   - Completely unused after switching to content-hash based resolution (commit 2e87329)
   - Still exists in duplicates.go for deduplication (different use case)

2. ReferenceScore field from CollisionDetail struct
   - Marked as DEPRECATED but never removed
   - No longer used by ScoreCollisions() which now uses content hashing

3. TestCountReferences and TestCountReferencesWordBoundary tests
   - Tested the now-deleted countReferences() function
   - No longer relevant

**Fixed:**
- Updated CheckpointWAL comments to remove misleading "staleness detection" claim
  - Staleness detection uses metadata (last_import_time), NOT file mtime
  - CheckpointWAL is still valuable for data persistence and WAL size reduction
  - Comments now accurately reflect actual benefits

**Verified:**
- All tests pass (internal/storage/sqlite)
- Content-hash collision resolution still works correctly
- No behavioral changes, just cleanup

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

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

.beads/beads.jsonl

@@ -67,7 +67,7 @@
 {"id":"bd-63","title":"Add internal/ai package for LLM integration","description":"Shared AI client for repair commands.\n\nProviders:\n- Anthropic (Claude)\n- OpenAI (GPT)\n- Ollama (local)\n\nEnv vars:\n- BEADS_AI_PROVIDER\n- BEADS_AI_API_KEY\n- BEADS_AI_MODEL\n\nFiles: internal/ai/client.go (new)","status":"open","priority":1,"issue_type":"task","created_at":"2025-10-28T14:48:29.072473-07:00","updated_at":"2025-10-28T14:48:29.072473-07:00","dependencies":[{"issue_id":"bd-63","depends_on_id":"bd-56","type":"blocks","created_at":"2025-10-28T14:48:29.073553-07:00","created_by":"daemon"}]}
 {"id":"bd-64","title":"Add embedding generation for duplicate detection","description":"Use embeddings for scalable duplicate detection.\n\nModel: text-embedding-3-small (OpenAI) or all-MiniLM-L6-v2 (local)\nStorage: SQLite vector extension or in-memory\nCost: ~/bin/bash.0002 per 100 issues\n\nMuch cheaper than LLM comparisons for large databases.\n\nFiles: internal/embeddings/ (new package)","status":"open","priority":2,"issue_type":"task","created_at":"2025-10-28T14:48:29.072913-07:00","updated_at":"2025-10-28T14:48:29.072913-07:00","dependencies":[{"issue_id":"bd-64","depends_on_id":"bd-56","type":"blocks","created_at":"2025-10-28T14:48:29.07486-07:00","created_by":"daemon"}]}
 {"id":"bd-65","title":"bd resolve-conflicts - Git merge conflict resolver","description":"Automatically resolve JSONL merge conflicts.\n\nModes:\n- Mechanical: ID remapping (no AI)\n- AI-assisted: Smart merge/keep decisions\n- Interactive: Review each conflict\n\nHandles \u003c\u003c\u003c\u003c\u003c\u003c\u003c conflict markers in .beads/beads.jsonl\n\nFiles: cmd/bd/resolve_conflicts.go (new)","status":"open","priority":1,"issue_type":"task","created_at":"2025-10-28T14:48:30.083642-07:00","updated_at":"2025-10-28T14:48:30.083642-07:00","dependencies":[{"issue_id":"bd-65","depends_on_id":"bd-56","type":"blocks","created_at":"2025-10-28T14:48:30.084575-07:00","created_by":"daemon"}]}
-{"id":"bd-66","title":"Add fallback to polling on watcher failure","description":"Detect fsnotify.NewWatcher() errors and log warning. Auto-switch to polling mode with 5s ticker. Add BEADS_WATCHER_FALLBACK env var to control behavior.","status":"closed","priority":1,"issue_type":"task","created_at":"2025-10-28T16:20:02.428439-07:00","updated_at":"2025-10-28T19:23:43.595916-07:00","closed_at":"2025-10-28T19:23:43.595916-07:00"}
+{"id":"bd-66","title":"Add fallback to polling on watcher failure","description":"Detect fsnotify.NewWatcher() errors and log warning. Auto-switch to polling mode with 5s ticker. Add BEADS_WATCHER_FALLBACK env var to control behavior.","status":"open","priority":1,"issue_type":"task","created_at":"2025-10-28T16:20:02.428439-07:00","updated_at":"2025-10-28T16:20:02.428439-07:00"}
 {"id":"bd-67","title":"Create cmd/bd/daemon_event_loop.go (~200 LOC)","description":"Implement runEventDrivenLoop to replace polling ticker. Coordinate FileWatcher, mutation events, debouncer. Include health check ticker (60s) for daemon validation.","status":"closed","priority":1,"issue_type":"task","created_at":"2025-10-28T16:20:02.429383-07:00","updated_at":"2025-10-28T16:20:02.429383-07:00","closed_at":"2025-10-28T12:30:44.067036-07:00"}
 {"id":"bd-68","title":"Add fsnotify dependency to go.mod","description":"","status":"in_progress","priority":1,"issue_type":"task","created_at":"2025-10-28T16:20:02.429763-07:00","updated_at":"2025-10-28T16:20:02.429763-07:00"}
 {"id":"bd-69","title":"Replace getStorageForRequest with Direct Access","description":"Replace all getStorageForRequest(req) calls with s.storage","acceptance_criteria":"- No references to getStorageForRequest() in codebase (except in deleted file)\n- All handlers use s.storage directly\n- Code compiles without errors\n\nFiles to update:\n- internal/rpc/server_issues_epics.go (~8 calls)\n- internal/rpc/server_labels_deps_comments.go (~4 calls)\n- internal/rpc/server_compact.go (~2 calls)\n- internal/rpc/server_export_import_auto.go (~2 calls)\n- internal/rpc/server_routing_validation_diagnostics.go (~1 call)\n\nPattern: store, err := s.getStorageForRequest(req) → store := s.storage","status":"closed","priority":1,"issue_type":"task","created_at":"2025-10-28T16:20:02.430127-07:00","updated_at":"2025-10-28T19:20:58.312809-07:00","closed_at":"2025-10-28T19:20:58.312809-07:00"}

internal/importer/importer.go

@@ -111,8 +111,7 @@ func ImportIssues(ctx context.Context, dbPath string, store storage.Storage, iss
 		return nil, err
 	}
 
-	// Checkpoint WAL to update main .db file timestamp
+	// Checkpoint WAL to ensure data persistence and reduce WAL file size
-	// This ensures staleness detection sees the database as fresh
 	if err := sqliteStore.CheckpointWAL(ctx); err != nil {
 		// Non-fatal - just log warning
 		fmt.Fprintf(os.Stderr, "Warning: failed to checkpoint WAL: %v\n", err)

internal/storage/sqlite/collision.go

@@ -31,7 +31,6 @@ type CollisionDetail struct {
 	IncomingIssue     *types.Issue  // The issue from the import file
 	ExistingIssue     *types.Issue  // The issue currently in the database
 	ConflictingFields []string      // List of field names that differ
-	ReferenceScore    int           // Number of references to this issue (for scoring) - DEPRECATED
 	RemapIncoming     bool          // If true, remap incoming; if false, remap existing
 }
 
@@ -271,62 +270,6 @@ func ScoreCollisions(ctx context.Context, s *SQLiteStorage, collisions []*Collis
 	return nil
 }
 
-// countReferences counts how many times an issue ID is referenced
-// Returns: text mentions + dependency references
-func countReferences(issueID string, allIssues []*types.Issue, allDeps map[string][]*types.Dependency) (int, error) {
-	count := 0
-
-	// Count text mentions in all issues' text fields
-	// Use word boundary regex to match exact IDs (e.g., "bd-10" but not "bd-100")
-	pattern := fmt.Sprintf(`\b%s\b`, regexp.QuoteMeta(issueID))
-	re, err := regexp.Compile(pattern)
-	if err != nil {
-		return 0, fmt.Errorf("failed to compile regex for %s: %w", issueID, err)
-	}
-
-	for _, issue := range allIssues {
-		// Skip counting references in the issue itself
-		if issue.ID == issueID {
-			continue
-		}
-
-		// Count mentions in description
-		count += len(re.FindAllString(issue.Description, -1))
-
-		// Count mentions in design
-		count += len(re.FindAllString(issue.Design, -1))
-
-		// Count mentions in notes
-		count += len(re.FindAllString(issue.Notes, -1))
-
-		// Count mentions in acceptance criteria
-		count += len(re.FindAllString(issue.AcceptanceCriteria, -1))
-	}
-
-	// Count dependency references
-	// An issue can be referenced as either IssueID or DependsOnID
-	for _, deps := range allDeps {
-		for _, dep := range deps {
-			// Skip self-references
-			if dep.IssueID == issueID && dep.DependsOnID == issueID {
-				continue
-			}
-
-			// Count if this issue is the source (IssueID)
-			if dep.IssueID == issueID {
-				count++
-			}
-
-			// Count if this issue is the target (DependsOnID)
-			if dep.DependsOnID == issueID {
-				count++
-			}
-		}
-	}
-
-	return count, nil
-}
-
 // deduplicateIncomingIssues removes content-duplicate issues within the incoming batch
 // Returns deduplicated slice, keeping the first issue ID (lexicographically) for each unique content
 func deduplicateIncomingIssues(issues []*types.Issue) []*types.Issue {

internal/storage/sqlite/collision_test.go

@@ -435,90 +435,6 @@ func intPtr(i int) *int {
 	return &i
 }
 
-func TestCountReferences(t *testing.T) {
-	allIssues := []*types.Issue{
-		{
-			ID:          "bd-1",
-			Title:       "Issue 1",
-			Description: "This mentions bd-2 and bd-3",
-			Design:      "Design mentions bd-2 twice: bd-2 and bd-2",
-			Notes:       "Notes mention bd-3",
-		},
-		{
-			ID:          "bd-2",
-			Title:       "Issue 2",
-			Description: "This mentions bd-1",
-		},
-		{
-			ID:          "bd-3",
-			Title:       "Issue 3",
-			Description: "No mentions here",
-		},
-		{
-			ID:          "bd-10",
-			Title:       "Issue 10",
-			Description: "This has bd-100 but not bd-10 itself",
-		},
-	}
-
-	allDeps := map[string][]*types.Dependency{
-		"bd-1": {
-			{IssueID: "bd-1", DependsOnID: "bd-2", Type: types.DepBlocks},
-		},
-		"bd-2": {
-			{IssueID: "bd-2", DependsOnID: "bd-3", Type: types.DepBlocks},
-		},
-	}
-
-	tests := []struct {
-		name          string
-		issueID       string
-		expectedCount int
-	}{
-		{
-			name:    "bd-1 - one text mention, one dependency",
-			issueID: "bd-1",
-			// Text: bd-2's description mentions bd-1 (1)
-			// Deps: bd-1 → bd-2 (1)
-			expectedCount: 2,
-		},
-		{
-			name:    "bd-2 - multiple text mentions, two dependencies",
-			issueID: "bd-2",
-			// Text: bd-1's description mentions bd-2 (1) + bd-1's design mentions bd-2 three times (3) = 4
-			//       (design has: "mentions bd-2" + "bd-2 and" + "bd-2")
-			// Deps: bd-1 → bd-2 (1) + bd-2 → bd-3 (1) = 2
-			expectedCount: 6,
-		},
-		{
-			name:    "bd-3 - some text mentions, one dependency",
-			issueID: "bd-3",
-			// Text: bd-1's description (1) + bd-1's notes (1) = 2
-			// Deps: bd-2 → bd-3 (1)
-			expectedCount: 3,
-		},
-		{
-			name:    "bd-10 - no mentions (bd-100 doesn't count)",
-			issueID: "bd-10",
-			// Text: bd-100 in bd-10's description doesn't match \bbd-10\b = 0
-			// Deps: none = 0
-			expectedCount: 0,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			count, err := countReferences(tt.issueID, allIssues, allDeps)
-			if err != nil {
-				t.Fatalf("countReferences failed: %v", err)
-			}
-			if count != tt.expectedCount {
-				t.Errorf("expected count %d, got %d", tt.expectedCount, count)
-			}
-		})
-	}
-}
-
 func TestScoreCollisions(t *testing.T) {
 	// Create temporary database
 	tmpDir, err := os.MkdirTemp("", "score-collision-test-*")
@@ -607,28 +523,24 @@ func TestScoreCollisions(t *testing.T) {
 	// Create collision details (simulated)
 	collisions := []*CollisionDetail{
 		{
-			ID:             "bd-1",
+			ID:            "bd-1",
-			IncomingIssue:  issue1,
+			IncomingIssue: issue1,
-			ExistingIssue:  issue1,
+			ExistingIssue: issue1,
-			ReferenceScore: 0, // Will be calculated
 		},
 		{
-			ID:             "bd-2",
+			ID:            "bd-2",
-			IncomingIssue:  issue2,
+			IncomingIssue: issue2,
-			ExistingIssue:  issue2,
+			ExistingIssue: issue2,
-			ReferenceScore: 0, // Will be calculated
 		},
 		{
-			ID:             "bd-3",
+			ID:            "bd-3",
-			IncomingIssue:  issue3,
+			IncomingIssue: issue3,
-			ExistingIssue:  issue3,
+			ExistingIssue: issue3,
-			ReferenceScore: 0, // Will be calculated
 		},
 		{
-			ID:             "bd-4",
+			ID:            "bd-4",
-			IncomingIssue:  issue4,
+			IncomingIssue: issue4,
-			ExistingIssue:  issue4,
+			ExistingIssue: issue4,
-			ReferenceScore: 0, // Will be calculated
 		},
 	}
 
@@ -656,67 +568,6 @@ func TestScoreCollisions(t *testing.T) {
 	}
 }
 
-func TestCountReferencesWordBoundary(t *testing.T) {
-	// Test that word boundaries work correctly
-	allIssues := []*types.Issue{
-		{
-			ID:          "bd-1",
-			Description: "bd-10 and bd-100 and bd-1 and bd-11",
-		},
-		{
-			ID:          "bd-10",
-			Description: "bd-1 and bd-100",
-		},
-	}
-
-	allDeps := map[string][]*types.Dependency{}
-
-	tests := []struct {
-		name          string
-		issueID       string
-		expectedCount int
-		description   string
-	}{
-		{
-			name:          "bd-1 exact match",
-			issueID:       "bd-1",
-			expectedCount: 2, // bd-10's desc mentions bd-1 (1) + bd-1's desc mentions bd-1 (1) = 2
-			// Wait, bd-1's desc shouldn't count itself
-			// So: bd-10's desc mentions bd-1 (1)
-		},
-		{
-			name:          "bd-10 exact match",
-			issueID:       "bd-10",
-			expectedCount: 1, // bd-1's desc mentions bd-10 (1)
-		},
-		{
-			name:          "bd-100 exact match",
-			issueID:       "bd-100",
-			expectedCount: 2, // bd-1's desc (1) + bd-10's desc (1)
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			count, err := countReferences(tt.issueID, allIssues, allDeps)
-			if err != nil {
-				t.Fatalf("countReferences failed: %v", err)
-			}
-
-			// Adjust expected based on actual counting logic
-			// countReferences skips the issue itself
-			expected := tt.expectedCount
-			if tt.issueID == testIssueBD1 {
-				expected = 1 // only bd-10's description
-			}
-
-			if count != expected {
-				t.Errorf("expected count %d, got %d", expected, count)
-			}
-		})
-	}
-}
-
 func TestReplaceIDReferences(t *testing.T) {
 	tests := []struct {
 		name      string
@@ -843,33 +694,31 @@ func TestRemapCollisions(t *testing.T) {
 
 	// Create collisions (incoming issues with same IDs as DB but different content)
 	collision1 := &CollisionDetail{
-		ID: "bd-2",
+		ID:            "bd-2",
 		ExistingIssue: dbIssue2,
 		IncomingIssue: &types.Issue{
 			ID:          "bd-2",
-			Title:       "Collision 2 (has fewer references)",
+			Title:       "Collision 2",
 			Description: "This is different content",
 			Status:      types.StatusOpen,
 			Priority:    1,
 			IssueType:   types.TypeTask,
 		},
-		RemapIncoming: true,  // Incoming will be remapped
+		RemapIncoming: true, // Incoming will be remapped
-		ReferenceScore: 2, // Fewer references
 	}
 
 	collision2 := &CollisionDetail{
-		ID: "bd-3",
+		ID:            "bd-3",
 		ExistingIssue: dbIssue3,
 		IncomingIssue: &types.Issue{
 			ID:          "bd-3",
-			Title:       "Collision 3 (has more references)",
+			Title:       "Collision 3",
 			Description: "Different content for bd-3",
 			Status:      types.StatusOpen,
 			Priority:    1,
 			IssueType:   types.TypeTask,
 		},
-		RemapIncoming: true,  // Incoming will be remapped
+		RemapIncoming: true, // Incoming will be remapped
-		ReferenceScore: 5, // More references
 	}
 
 	collisions := []*CollisionDetail{collision1, collision2}
@@ -903,7 +752,7 @@ func TestRemapCollisions(t *testing.T) {
 	if remappedIssue2 == nil {
 		t.Fatalf("remapped issue %s not found", newID2)
 	}
-	if remappedIssue2.Title != "Collision 2 (has fewer references)" {
+	if remappedIssue2.Title != "Collision 2" {
 		t.Errorf("unexpected title for remapped issue: %s", remappedIssue2.Title)
 	}
 

internal/storage/sqlite/sqlite.go

@@ -2301,9 +2301,11 @@ func (s *SQLiteStorage) UnderlyingConn(ctx context.Context) (*sql.Conn, error) {
 }
 
 // CheckpointWAL checkpoints the WAL file to flush changes to the main database file.
-// This updates the main .db file's modification time, which is important for staleness detection.
 // In WAL mode, writes go to the -wal file, leaving the main .db file untouched.
-// Checkpointing flushes the WAL to the main database file.
+// Checkpointing:
+// - Ensures data persistence by flushing WAL to main database
+// - Reduces WAL file size
+// - Makes database safe for backup/copy operations
 func (s *SQLiteStorage) CheckpointWAL(ctx context.Context) error {
 	_, err := s.db.ExecContext(ctx, "PRAGMA wal_checkpoint(FULL)")
 	return err