Add unit tests to improve cmd/bd CLI coverage (bd-llfl)

Added 479 lines of new tests:

- utils_unit_test.go: Tests for utility functions (truncateString,
  pluralize, formatTimeAgo, containsLabel, extractIDSuffix, truncate,
  truncateDescription, showCleanupDeprecationHint, clearAutoFlushState)

- hooks_test.go: Tests for FormatHookWarnings, isRebaseInProgress,
  hasBeadsJSONL

- list_test.go: Tests for formatIssueLong, formatIssueCompact

- version_tracking_test.go: Fixed flaky tests by setting BEADS_DIR
  env var to prevent git worktree detection from finding the actual
  .beads directory instead of the temp directory

Coverage increased from 21.6% to 22.0%. The remaining 78% of untested
code involves daemon/RPC operations, command handlers requiring
database/daemon setup, and git operations that would require
integration tests with mocked dependencies.

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

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

cmd/bd/version_tracking_test.go

@@ -134,6 +134,10 @@ func TestTrackBdVersion_FirstRun(t *testing.T) {
 		t.Fatalf("Failed to create db file: %v", err)
 	}
 
+	// Set BEADS_DIR to force FindBeadsDir to use our temp directory
+	// This prevents finding the actual .beads in a git worktree
+	t.Setenv("BEADS_DIR", beadsDir)
+
 	// Change to temp directory
 	t.Chdir(tmpDir)
 
@@ -176,6 +180,10 @@ func TestTrackBdVersion_UpgradeDetection(t *testing.T) {
 		t.Fatalf("Failed to create .beads: %v", err)
 	}
 
+	// Set BEADS_DIR to force FindBeadsDir to use our temp directory
+	// This prevents finding the actual .beads in a git worktree
+	t.Setenv("BEADS_DIR", beadsDir)
+
 	// Change to temp directory
 	t.Chdir(tmpDir)