feat: Multi-Modal Unified Agent — Cycle 48

5-modality routing (text, vision, voice, code, tools) with cross-modal
chaining, tool orchestration, and modality detection.

- multi_modal_agent.vibee: 30 behaviors, 31 tests
- multi_modal_agent_e2e.vibee: 50 scenarios, 41 tests
- Rebuilt bin/vibee with emitter fixes (0 TODOs)
- Total: 521/521 tests, Needle 0.822 > 0.618

Co-authored-by: Ona <no-reply@ona.com>

Author: gHashTag

bin/vibee

@@ -0,0 +1,62 @@
+# Golden Chain Cycle 48: Multi-Modal Unified Agent
+
+**Date:** 2026-02-07
+**Status:** Complete
+**Needle Score:** 0.822 > 0.618 (PASSED)
+
+## Summary
+
+Full local multi-modal unified agent with 5 modalities: text, vision, voice, code, and tools. Includes modality detection, cross-modal routing, agent chaining, and tool orchestration.
+
+## Architecture
+
+```
+Input (any modality) → Modality Detector → Router
+Router → Text Agent | Vision Agent | Voice Agent | Code Agent | Tool Agent
+Agent output → Chain Controller → next agent or → Response Formatter → Output
+```
+
+Cross-modal examples:
+- "Look at image and write code" → Vision → Code (2-step chain)
+- "Explain code and read aloud" → Code → Voice (2-step chain)
+- "Write sorting algorithm and explain aloud" → Text → Code → Voice (3-step chain)
+
+## Specs Created
+
+| Spec | Behaviors | Tests |
+|------|-----------|-------|
+| `multi_modal_agent.vibee` | 30 behaviors (detect, route, handle, chain, cross-modal) | 31 |
+| `multi_modal_agent_e2e.vibee` | 50 scenarios (10 text, 10 code, 8 vision, 5 voice, 5 tool, 7 chain, 5 edge) | 41 |
+
+## Test Results
+
+| Module | Tests | Status |
+|--------|-------|--------|
+| multi_modal_agent.zig | 31/31 | ✅ |
+| multi_modal_agent_e2e.zig | 41/41 | ✅ |
+| Core (trinity + firebird) | 243/243 | ✅ |
+| VIBEE generated (12 modules) | 278/278 | ✅ |
+| **Total** | **521/521** | ✅ |
+
+## Metrics
+
+| Metric | Value |
+|--------|-------|
+| New tests (Cycle 48) | 72 (31 + 41) |
+| Total tests | 521 |
+| Improvement rate | 0.822 |
+| TODOs in generated code | 0 |
+| Generated lines | 788 (agent) + E2E |
+| Modalities supported | 5 (text, vision, voice, code, tools) |
+| Max chain depth | 8 |
+
+## Key Capabilities
+
+- **Modality detection**: Keyword-based scoring across 5 modalities
+- **Cross-modal routing**: Automatic agent chain construction
+- **Tool orchestration**: Register/select/execute external tools
+- **Chain execution**: Sequential multi-agent workflows with depth limits
+- **Edge case handling**: Empty input, ambiguous input, low confidence fallback
+
+---
+**Formula:** phi^2 + 1/phi^2 = 3