[eric] backend: add per-lifespan boot timing to pin cold-start stalls

- debug(sub_app.name) is a no-op in packaged builds, so the packaged backend.log
  had zero per-SubApp markers and a cold stall could only be guessed at
- wrap each enter_async_context with time.perf_counter + a flushed [perf] print,
  plus a lifespans-total line, so a cold launch names the exact slow lifespan
- logging only, no functional change; loop logic validated warm

backend/config/Apps.py

@@ -1,4 +1,5 @@
 import os
+import time
 
 from fastapi import FastAPI, APIRouter
 import debug
@@ -29,9 +30,18 @@ class MainApp:
         @asynccontextmanager
         async def lifespan(app: FastAPI):
             async with AsyncExitStack() as stack:
+                # [perf] per-lifespan boot timing. debug() is a no-op in the
+                # packaged build, so without this the packaged backend.log has no
+                # per-SubApp markers and a cold-start stall can only be guessed at.
+                # One perf_counter + flushed print per app pins exactly which
+                # lifespan (or the cold first-touch I/O entering it) dominates.
+                _boot_t0 = time.perf_counter()
                 for sub_app in sub_apps:
                     debug(sub_app.name)
+                    _t0 = time.perf_counter()
                     await stack.enter_async_context(sub_app.lifespan())
+                    print(f"[perf] lifespan {sub_app.name} t={(time.perf_counter() - _t0) * 1000:.0f}ms", flush=True)
+                print(f"[perf] lifespans-total t={(time.perf_counter() - _boot_t0) * 1000:.0f}ms", flush=True)
                 _port = os.environ.get("OPENSWARM_PORT", "8324")
                 print(f"\nCheck out the API docs at: http://127.0.0.1:{_port}/docs\n")
                 yield