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/sync_helpers_more_test.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/steveyegge/beads/internal/config"
+)
+
+func TestBuildGitCommitArgs_ConfigOptions(t *testing.T) {
+	if err := config.Initialize(); err != nil {
+		t.Fatalf("config.Initialize: %v", err)
+	}
+	config.Set("git.author", "Test User <test@example.com>")
+	config.Set("git.no-gpg-sign", true)
+
+	args := buildGitCommitArgs("/repo", "hello", "--", ".beads")
+	joined := strings.Join(args, " ")
+	if !strings.Contains(joined, "--author") {
+		t.Fatalf("expected --author in args: %v", args)
+	}
+	if !strings.Contains(joined, "--no-gpg-sign") {
+		t.Fatalf("expected --no-gpg-sign in args: %v", args)
+	}
+	if !strings.Contains(joined, "-m hello") {
+		t.Fatalf("expected message in args: %v", args)
+	}
+}
+
+func TestGitCommitBeadsDir_PathspecDoesNotCommitOtherStagedFiles(t *testing.T) {
+	_, cleanup := setupGitRepo(t)
+	defer cleanup()
+
+	if err := config.Initialize(); err != nil {
+		t.Fatalf("config.Initialize: %v", err)
+	}
+
+	if err := os.MkdirAll(".beads", 0o755); err != nil {
+		t.Fatalf("MkdirAll: %v", err)
+	}
+
+	// Stage an unrelated file before running gitCommitBeadsDir.
+	if err := os.WriteFile("other.txt", []byte("x\n"), 0o600); err != nil {
+		t.Fatalf("WriteFile other: %v", err)
+	}
+	_ = exec.Command("git", "add", "other.txt").Run()
+
+	// Create a beads sync file to commit.
+	issuesPath := filepath.Join(".beads", "issues.jsonl")
+	if err := os.WriteFile(issuesPath, []byte("{\"id\":\"test-1\"}\n"), 0o600); err != nil {
+		t.Fatalf("WriteFile issues: %v", err)
+	}
+
+	ctx := context.Background()
+	if err := gitCommitBeadsDir(ctx, "beads commit"); err != nil {
+		t.Fatalf("gitCommitBeadsDir: %v", err)
+	}
+
+	// other.txt should still be staged after the beads-only commit.
+	out, err := exec.Command("git", "diff", "--cached", "--name-only").CombinedOutput()
+	if err != nil {
+		t.Fatalf("git diff --cached: %v\n%s", err, out)
+	}
+	if strings.TrimSpace(string(out)) != "other.txt" {
+		t.Fatalf("expected other.txt still staged, got: %q", out)
+	}
+}