feat(beads): add Release function and gt release command

Implement step recovery mechanism for stuck molecule steps (MVP):
- Add Release() and ReleaseWithReason() to beads wrapper
- Create gt release command to move in_progress → open
- Clears assignee so step can be claimed by another worker
- Optionally adds reason as note for tracking

Usage:
  gt release <id>           # Release single issue
  gt release <id> -r "why"  # Release with reason

This enables nondeterministic idempotence - stuck steps can be
safely recovered and retried by releasing and reclaiming.

Closes gt-g44u.4

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

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

internal/cmd/release.go

@@ -0,0 +1,77 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/gastown/internal/beads"
+	"github.com/steveyegge/gastown/internal/style"
+)
+
+var releaseReason string
+
+var releaseCmd = &cobra.Command{
+	Use:   "release <issue-id>...",
+	Short: "Release stuck in_progress issues back to pending",
+	Long: `Release one or more in_progress issues back to open/pending status.
+
+This is used to recover stuck steps when a worker dies mid-task.
+The issue is moved to "open" status and the assignee is cleared,
+allowing another worker to claim and complete it.
+
+Examples:
+  gt release gt-abc           # Release single issue
+  gt release gt-abc gt-def    # Release multiple issues
+  gt release gt-abc -r "worker died"  # Release with reason
+
+This implements nondeterministic idempotence - work can be safely
+retried by releasing and reclaiming stuck steps.`,
+	Args: cobra.MinimumNArgs(1),
+	RunE: runRelease,
+}
+
+func init() {
+	releaseCmd.Flags().StringVarP(&releaseReason, "reason", "r", "", "Reason for releasing (added as note)")
+	rootCmd.AddCommand(releaseCmd)
+}
+
+func runRelease(cmd *cobra.Command, args []string) error {
+	// Get working directory for beads
+	cwd, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("getting working directory: %w", err)
+	}
+
+	bd := beads.New(cwd)
+
+	// Release each issue
+	var released, failed int
+	for _, id := range args {
+		var err error
+		if releaseReason != "" {
+			err = bd.ReleaseWithReason(id, releaseReason)
+		} else {
+			err = bd.Release(id)
+		}
+
+		if err != nil {
+			fmt.Printf("%s Failed to release %s: %v\n", style.Dim.Render("✗"), id, err)
+			failed++
+		} else {
+			fmt.Printf("%s Released %s → open\n", style.Bold.Render("✓"), id)
+			released++
+		}
+	}
+
+	// Summary if multiple
+	if len(args) > 1 {
+		fmt.Printf("\nReleased: %d, Failed: %d\n", released, failed)
+	}
+
+	if failed > 0 {
+		return fmt.Errorf("%d issue(s) failed to release", failed)
+	}
+
+	return nil
+}