terminology: spawn → pour/wisp for molecules (gt-9uy0)

Molecules use chemistry verbs, not spawn:
- pour = create persistent mol (liquid)
- wisp = create ephemeral wisp (vapor)
- spawn = polecats only (workers)

Changes:
- Delete chemistry-design-changes.md (migration doc)
- Remove migration tables from sling-design.md
- Update bond tables: Spawn → Pour/Wisp
- Rename spawnMoleculeFromProto → pourMoleculeFromProto
- Rename spawnMoleculeOnIssue → runMoleculeOnIssue
- Update templates: bd mol spawn → bd wisp
- Update prime.go: commands and messages
- Clean all docs and comments

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

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

internal/templates/roles/witness.md.tmpl

@@ -97,7 +97,7 @@ gt mail inbox
 gt mol attach-from-mail <mail-id>
 
 # Step 4: Still nothing? Create patrol wisp
-bd wisp mol-witness-patrol --assignee={{ .RigName }}/witness
+gt wisp mol-witness-patrol --assignee={{ .RigName }}/witness
 ```
 
 **Hook → Execute. No exceptions.**