Implement consistency architecture (10-principle framework)

Adds:
- ARCHITECTURE.md: Full documentation of 3-layer system
- Context Pipeline: Preprocessing layer (pipeline.js)
- Workflow Router: 4 fixed workflows (coding, debug, deploy, audit)
- Validation Layer: Post-response quality gate (validator.js)
- Format Templates: Structured output templates
- TOOLS.md: Beavault connection documentation

Architecture:
- Layer 1: Behavior rules (always injected)
- Layer 2: Persistent facts (structured memory)
- Layer 3: Ephemeral context
- Priority enforcement: Rules > Prefs > Task > Chat
- Memory write policy: Only confirmed fixes, repeated preferences

templates/code-change.md

@@ -0,0 +1,17 @@
+## Summary
+[What changed]
+
+## Files Modified
+- `file1.py`: [description]
+- `file2.js`: [description]
+
+## Verification
+- [ ] Tests pass
+- [ ] Lint passes  
+- [ ] Manual verification complete
+
+## Decisions Made
+- [decision]
+
+## Still Open
+- [if any]