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/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"os"
 	"os/signal"
@@ -312,6 +313,9 @@ var rootCmd = &cobra.Command{
 		// Set up signal-aware context for graceful cancellation
 		rootCtx, rootCancel = signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 
+		// Signal Gas Town daemon about bd activity (best-effort, for exponential backoff)
+		defer signalGasTownActivity()
+
 		// Apply verbosity flags early (before any output)
 		debug.SetVerbose(verboseFlag)
 		debug.SetQuiet(quietFlag)
@@ -623,6 +627,13 @@ var rootCmd = &cobra.Command{
 			FallbackReason:   FallbackNone,
 		}
 
+		// Doctor should always run in direct mode. It's specifically used to diagnose and
+		// repair daemon/DB issues, so attempting to connect to (or auto-start) a daemon
+		// can add noise and timeouts.
+		if cmd.Name() == "doctor" {
+			noDaemon = true
+		}
+
 		// Try to connect to daemon first (unless --no-daemon flag is set or worktree safety check fails)
 		if noDaemon {
 			daemonStatus.FallbackReason = FallbackFlagNoDaemon
@@ -864,6 +875,9 @@ var rootCmd = &cobra.Command{
 				debug.Logf("loaded %d molecules from %v", result.Loaded, result.Sources)
 			}
 		}
+
+		// Tips (including sync conflict proactive checks) are shown via maybeShowTip()
+		// after successful command execution, not in PreRun
 	},
 	PersistentPostRun: func(cmd *cobra.Command, args []string) {
 		// Handle --no-db mode: write memory storage back to JSONL
@@ -917,8 +931,14 @@ var rootCmd = &cobra.Command{
 		if store != nil {
 			_ = store.Close()
 		}
-		if profileFile != nil { pprof.StopCPUProfile(); _ = profileFile.Close() }
-		if traceFile != nil { trace.Stop(); _ = traceFile.Close() }
+		if profileFile != nil {
+			pprof.StopCPUProfile()
+			_ = profileFile.Close()
+		}
+		if traceFile != nil {
+			trace.Stop()
+			_ = traceFile.Close()
+		}
 
 		// Cancel the signal context to clean up resources
 		if rootCancel != nil {
@@ -931,6 +951,80 @@ var rootCmd = &cobra.Command{
 // Configurable via config file or BEADS_FLUSH_DEBOUNCE env var (e.g., "500ms", "10s")
 // Defaults to 5 seconds if not set or invalid
 
+// signalGasTownActivity writes an activity signal for Gas Town daemon.
+// This enables exponential backoff based on bd usage detection (gt-ws8ol).
+// Best-effort: silent on any failure, never affects bd operation.
+func signalGasTownActivity() {
+	// Determine town root
+	// Priority: GT_ROOT env > detect from cwd path > skip
+	townRoot := os.Getenv("GT_ROOT")
+	if townRoot == "" {
+		// Try to detect from cwd - if under ~/gt/, use that as town root
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return
+		}
+		gtRoot := filepath.Join(home, "gt")
+		cwd, err := os.Getwd()
+		if err != nil {
+			return
+		}
+		if strings.HasPrefix(cwd, gtRoot+string(os.PathSeparator)) {
+			townRoot = gtRoot
+		}
+	}
+
+	if townRoot == "" {
+		return // Not in Gas Town, skip
+	}
+
+	// Ensure daemon directory exists
+	daemonDir := filepath.Join(townRoot, "daemon")
+	if err := os.MkdirAll(daemonDir, 0755); err != nil {
+		return
+	}
+
+	// Build command line from os.Args
+	cmdLine := strings.Join(os.Args, " ")
+
+	// Determine actor (use package-level var if set, else fall back to env)
+	actorName := actor
+	if actorName == "" {
+		if bdActor := os.Getenv("BD_ACTOR"); bdActor != "" {
+			actorName = bdActor
+		} else if user := os.Getenv("USER"); user != "" {
+			actorName = user
+		} else {
+			actorName = "unknown"
+		}
+	}
+
+	// Build activity signal
+	activity := struct {
+		LastCommand string `json:"last_command"`
+		Actor       string `json:"actor"`
+		Timestamp   string `json:"timestamp"`
+	}{
+		LastCommand: cmdLine,
+		Actor:       actorName,
+		Timestamp:   time.Now().UTC().Format(time.RFC3339),
+	}
+
+	data, err := json.Marshal(activity)
+	if err != nil {
+		return
+	}
+
+	// Write atomically (write to temp, rename)
+	activityPath := filepath.Join(daemonDir, "activity.json")
+	tmpPath := activityPath + ".tmp"
+	// nolint:gosec // G306: 0644 is appropriate for a status file
+	if err := os.WriteFile(tmpPath, data, 0644); err != nil {
+		return
+	}
+	_ = os.Rename(tmpPath, activityPath)
+}
+
 func main() {
 	if err := rootCmd.Execute(); err != nil {
 		os.Exit(1)