Fix BLOCKER BUG: wrong keyword argument in generate_flow route

Route passed format=format but service method expects fmt=fmt.
This caused a crash when hitting /api/flow/{view}.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aksOps

src/osscodeiq/server/routes.py

@@ -113,8 +113,8 @@ async def dependents_of(module_id: str):
     # ── Flow ─────────────────────────────────────────────────────────────
 
     @router.get("/flow/{view}")
-    async def generate_flow(view: str, format: str = "json"):
-        return service.generate_flow(view, format=format)
+    async def generate_flow(view: str, fmt: str = "json"):
+        return service.generate_flow(view, fmt=fmt)
 
     @router.get("/flow")
     async def generate_all_flows():