Add gt mol catalog/burn/squash, wire wisp flag, update deacon prompt

- gt mol catalog: list available molecule protos
- gt mol burn: burn current molecule without digest
- gt mol squash: compress molecule into digest
- Wire --wisp flag in gt sling to use .beads-wisp/ storage
- Add IsWisp field to MoleculeContext
- Update prompts/roles/deacon.md with correct commands

Closes: gt-x74c, gt-9t14, gt-i4i2

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

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

internal/cmd/spawn.go

@@ -584,6 +584,7 @@ type MoleculeContext struct {
 	RootIssueID string // The spawned molecule root issue
 	TotalSteps  int    // Total number of steps in the molecule
 	StepNumber  int    // Which step this is (1-indexed)
+	IsWisp      bool   // True if this is an ephemeral wisp molecule
 }
 
 // buildWorkAssignmentMail creates a work assignment mail message for a polecat.