feat: complete Event Log, Ledger, Memory, Cascade Router, Upgrade Queue, Activity Feed

This commit implements six major features:

1. Event Log System (src/swarm/event_log.py)
   - SQLite-based audit trail for all swarm events
   - Task lifecycle tracking (created, assigned, completed, failed)
   - Agent lifecycle tracking (joined, left, status changes)
   - Integrated with coordinator for automatic logging
   - Dashboard page at /swarm/events

2. Lightning Ledger (src/lightning/ledger.py)
   - Transaction tracking for Lightning Network payments
   - Balance calculations (incoming, outgoing, net, available)
   - Integrated with payment_handler for automatic logging
   - Dashboard page at /lightning/ledger

3. Semantic Memory / Vector Store (src/memory/vector_store.py)
   - Embedding-based similarity search for Echo agent
   - Fallback to keyword matching if sentence-transformers unavailable
   - Personal facts storage and retrieval
   - Dashboard page at /memory

4. Cascade Router Integration (src/timmy/cascade_adapter.py)
   - Automatic LLM failover between providers (Ollama → AirLLM → API)
   - Circuit breaker pattern for failing providers
   - Metrics tracking per provider (latency, error rates)
   - Dashboard status page at /router/status

5. Self-Upgrade Approval Queue (src/upgrades/)
   - State machine for self-modifications: proposed → approved/rejected → applied/failed
   - Human approval required before applying changes
   - Git integration for branch management
   - Dashboard queue at /self-modify/queue

6. Real-Time Activity Feed (src/events/broadcaster.py)
   - WebSocket-based live activity streaming
   - Bridges event_log to dashboard clients
   - Activity panel on /swarm/live

Tests:
- 101 unit tests passing
- 4 new E2E test files for Selenium testing
- Run with: SELENIUM_UI=1 pytest tests/functional/ -v --headed

Documentation:
- 6 ADRs (017-022) documenting architecture decisions
- Implementation summary in docs/IMPLEMENTATION_SUMMARY.md
- Architecture diagram in docs/architecture-v2.md

src/dashboard/routes/memory.py

@@ -0,0 +1,98 @@
+"""Memory (vector store) routes for browsing and searching memories."""
+
+from pathlib import Path
+from typing import Optional
+
+from fastapi import APIRouter, Form, Request
+from fastapi.responses import HTMLResponse
+from fastapi.templating import Jinja2Templates
+
+from memory.vector_store import (
+    store_memory,
+    search_memories,
+    get_memory_stats,
+    recall_personal_facts,
+    store_personal_fact,
+)
+
+router = APIRouter(prefix="/memory", tags=["memory"])
+templates = Jinja2Templates(directory=str(Path(__file__).parent.parent / "templates"))
+
+
+@router.get("", response_class=HTMLResponse)
+async def memory_page(
+    request: Request,
+    query: Optional[str] = None,
+    context_type: Optional[str] = None,
+    agent_id: Optional[str] = None,
+):
+    """Memory browser and search page."""
+    results = []
+    if query:
+        results = search_memories(
+            query=query,
+            context_type=context_type,
+            agent_id=agent_id,
+            limit=20,
+        )
+    
+    stats = get_memory_stats()
+    facts = recall_personal_facts(limit=10)
+    
+    return templates.TemplateResponse(
+        request,
+        "memory.html",
+        {
+            "page_title": "Memory Browser",
+            "query": query,
+            "results": results,
+            "stats": stats,
+            "facts": facts,
+            "filter_type": context_type,
+            "filter_agent": agent_id,
+        },
+    )
+
+
+@router.post("/search", response_class=HTMLResponse)
+async def memory_search(
+    request: Request,
+    query: str = Form(...),
+    context_type: Optional[str] = Form(None),
+):
+    """Search memories (form submission)."""
+    results = search_memories(
+        query=query,
+        context_type=context_type,
+        limit=20,
+    )
+    
+    # Return partial for HTMX
+    return templates.TemplateResponse(
+        request,
+        "partials/memory_results.html",
+        {
+            "query": query,
+            "results": results,
+        },
+    )
+
+
+@router.post("/fact", response_class=HTMLResponse)
+async def add_fact(
+    request: Request,
+    fact: str = Form(...),
+    agent_id: Optional[str] = Form(None),
+):
+    """Add a personal fact to memory."""
+    store_personal_fact(fact, agent_id=agent_id)
+    
+    # Return updated facts list
+    facts = recall_personal_facts(limit=10)
+    return templates.TemplateResponse(
+        request,
+        "partials/memory_facts.html",
+        {
+            "facts": facts,
+        },
+    )