Rename Engineer in Box to Shiny (gt-8tmz.10)

Renamed mol-engineer-in-box to mol-shiny across all documentation
and test code. This is a Mad Max reference - the canonical 'right
way to engineer'.

Files updated:
- docs/architecture.md (15 references)
- docs/molecules.md (7 references)
- docs/bootstrap.md (1 reference)
- docs/molecular-chemistry.md (1 reference)
- docs/polecat-wisp-architecture.md (1 reference)
- internal/beads/molecule_test.go (test function rename)

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

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

docs/molecular-chemistry.md

@@ -693,7 +693,7 @@ Gas Town maintains a **library of curated protos** - the fuel stockpile:
 
 ```
 ~/gt/molecules/
-├── mol-engineer-in-box/       # Full quality workflow
+├── mol-shiny/                 # Full quality workflow
 ├── mol-quick-fix/             # Fast path for small changes
 ├── mol-code-review/           # Pluggable review dimensions
 ├── mol-release/               # Release workflow