refactor: remove unused bd pin/unpin/hook commands (bd-x0zl)

Analysis found these commands are dead code:
- gt never calls `bd pin` - uses `bd update --status=pinned` instead
- Beads.Pin() wrapper exists but is never called
- bd hook functionality duplicated by gt mol status
- Code comment says "pinned field is cosmetic for bd hook visibility"

Removed:
- cmd/bd/pin.go
- cmd/bd/unpin.go
- cmd/bd/hook.go

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

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

cmd/bd/nodb_test.go

@@ -158,6 +158,90 @@ func TestDetectPrefix(t *testing.T) {
 	})
 }
 
+func TestInitializeNoDbMode_SetsStoreActive(t *testing.T) {
+	// This test verifies the fix for bd comment --no-db not working.
+	// The bug was that initializeNoDbMode() set `store` but not `storeActive`,
+	// so ensureStoreActive() would try to find a SQLite database.
+
+	tempDir := t.TempDir()
+	beadsDir := filepath.Join(tempDir, ".beads")
+	if err := os.MkdirAll(beadsDir, 0o755); err != nil {
+		t.Fatalf("Failed to create .beads dir: %v", err)
+	}
+
+	// Create a minimal JSONL file with one issue
+	jsonlPath := filepath.Join(beadsDir, "issues.jsonl")
+	content := `{"id":"bd-1","title":"Test Issue","status":"open"}
+`
+	if err := os.WriteFile(jsonlPath, []byte(content), 0o600); err != nil {
+		t.Fatalf("Failed to write JSONL: %v", err)
+	}
+
+	// Save and restore global state
+	oldStore := store
+	oldStoreActive := storeActive
+	oldCwd, _ := os.Getwd()
+	defer func() {
+		storeMutex.Lock()
+		store = oldStore
+		storeActive = oldStoreActive
+		storeMutex.Unlock()
+		_ = os.Chdir(oldCwd)
+	}()
+
+	// Change to temp dir so initializeNoDbMode finds .beads
+	if err := os.Chdir(tempDir); err != nil {
+		t.Fatalf("Failed to chdir: %v", err)
+	}
+
+	// Reset global state
+	storeMutex.Lock()
+	store = nil
+	storeActive = false
+	storeMutex.Unlock()
+
+	// Initialize no-db mode
+	if err := initializeNoDbMode(); err != nil {
+		t.Fatalf("initializeNoDbMode failed: %v", err)
+	}
+
+	// Verify storeActive is now true
+	storeMutex.Lock()
+	active := storeActive
+	s := store
+	storeMutex.Unlock()
+
+	if !active {
+		t.Error("storeActive should be true after initializeNoDbMode")
+	}
+	if s == nil {
+		t.Fatal("store should not be nil after initializeNoDbMode")
+	}
+
+	// ensureStoreActive should now return immediately without error
+	if err := ensureStoreActive(); err != nil {
+		t.Errorf("ensureStoreActive should succeed after initializeNoDbMode: %v", err)
+	}
+
+	// Verify comments work (this was the failing case)
+	ctx := rootCtx
+	comment, err := s.AddIssueComment(ctx, "bd-1", "testuser", "Test comment")
+	if err != nil {
+		t.Fatalf("AddIssueComment failed: %v", err)
+	}
+	if comment.Text != "Test comment" {
+		t.Errorf("Expected 'Test comment', got %s", comment.Text)
+	}
+
+	comments, err := s.GetIssueComments(ctx, "bd-1")
+	if err != nil {
+		t.Fatalf("GetIssueComments failed: %v", err)
+	}
+	if len(comments) != 1 {
+		t.Errorf("Expected 1 comment, got %d", len(comments))
+	}
+}
+
 func TestWriteIssuesToJSONL(t *testing.T) {
 	tempDir := t.TempDir()
 	beadsDir := filepath.Join(tempDir, ".beads")