fix: add missing federation /v1/federation/vote endpoint

- Added POST /v1/federation/vote endpoint to handle peer generation requests
- Peers were discovering each other but requests had no endpoint to hit
- Endpoint generates using local swarm and returns vote results
- Logs federation requests for debugging
- All 41 tests passing

src/api/routes.py

@@ -412,3 +412,54 @@ async def chat_completions(request: ChatCompletionRequest, fastapi_request: Requ
         logger.error(f"Error type: {type(e).__name__}")
         logger.error(f"Error message: {str(e)}")
         raise HTTPException(status_code=500, detail=f"Generation failed: {str(e)}")
+
+
+# Federation endpoint for peer-to-peer generation
+@router.post("/v1/federation/vote")
+async def federation_vote(request: Request):
+    """Handle federation vote request from a peer swarm.
+    
+    This endpoint allows peer swarms to request generation from this swarm
+    as part of the federation consensus process.
+    """
+    try:
+        data = await request.json()
+        prompt = data.get("prompt", "")
+        max_tokens = data.get("max_tokens", 1024)
+        temperature = data.get("temperature", 0.7)
+        
+        logger.info(f"🗳️  Federation vote request from {request.client.host}")
+        logger.debug(f"   Prompt: {prompt[:100]}...")
+        
+        # Get swarm manager from app state
+        swarm_manager = getattr(request.app.state, 'swarm_manager', None)
+        
+        if not swarm_manager:
+            raise HTTPException(status_code=503, detail="Swarm not ready")
+        
+        # Generate response
+        start_time = time.time()
+        result = await swarm_manager.generate(
+            prompt=prompt,
+            max_tokens=max_tokens,
+            temperature=temperature,
+            use_consensus=True
+        )
+        
+        elapsed_ms = (time.time() - start_time) * 1000
+        response = result.selected_response
+        
+        logger.info(f"✅ Federation vote complete ({response.tokens_generated} tokens, {elapsed_ms:.0f}ms)")
+        
+        return {
+            "response": response.text,
+            "confidence": 0.8,  # Could be calculated from consensus
+            "latency_ms": elapsed_ms,
+            "worker_count": len(swarm_manager.workers) if hasattr(swarm_manager, 'workers') else 1,
+            "tokens_per_second": response.tokens_per_second,
+            "tokens_generated": response.tokens_generated
+        }
+        
+    except Exception as e:
+        logger.exception("Error handling federation vote")
+        raise HTTPException(status_code=500, detail=f"Federation vote failed: {str(e)}")