feat(monitoring): observability stack + app instrumentation

- /health/ready (DB+MinIO+Casdoor checks, webhook post-deploy gate),
  /metrics via prometheus-fastapi-instrumentator, Sentry/GlitchTip capture,
  X-Request-ID middleware + JSON access logging (PROCUREMENT_LOG_FORMAT)
- server-side analytics (OpenPanel Track API): login, quote lifecycle,
  receipts — fire-and-forget, disabled without env config
- monitoring/ compose project: GlitchTip(+pg), Prometheus(+alerts),
  Grafana(provisioned ERP dashboard), Loki+Promtail, node/postgres
  exporters, cAdvisor — mem-limited (~2.2GB), loopback admin UIs,
  separate from app deploys; erp_shared network for scraping
- frontend: @openpanel/web + @sentry/react (build-arg gated, no-op when
  unset), funnel events (login, wizard steps, quote submitted)
- compose: api healthcheck, observability env wiring, .env.example keys

backend/app/main.py

@@ -7,12 +7,16 @@
 """
 import asyncio
 import logging
+import uuid
 from contextlib import asynccontextmanager
 
+import httpx
 from fastapi import Depends, FastAPI, Request
 from fastapi.exceptions import RequestValidationError
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
+from prometheus_fastapi_instrumentator import Instrumentator
+from sqlalchemy import text as sql_text
 from sqlalchemy.exc import IntegrityError
 
 from app.auth import get_current_user
@@ -25,13 +29,29 @@ from app.db.init_db import (
     ensure_quote_projects,
     ensure_v26,
 )
+from app.observability import RequestContextMiddleware, setup_logging
 from app.routers import ROUTERS
 from app.services.quote_service import auto_expire_quotes
 from app.utils.errors import AppError
 
-logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s — %(message)s")
+setup_logging(settings.LOG_FORMAT)
 logger = logging.getLogger("procurement")
 
+if settings.SENTRY_DSN:
+    # GlitchTip/Sentry exception capture — after setup_logging so the SDK's
+    # own logs go through our formatter too. Disabled entirely without a DSN.
+    import sentry_sdk
+    from sentry_sdk.integrations.fastapi import FastApiIntegration
+
+    sentry_sdk.init(
+        dsn=settings.SENTRY_DSN,
+        environment=settings.ENVIRONMENT,
+        traces_sample_rate=settings.SENTRY_TRACES_SAMPLE_RATE,
+        integrations=[FastApiIntegration()],
+        send_default_pii=False,
+    )
+    logger.info("Sentry/GlitchTip exception capture enabled")
+
 API_V1_PREFIX = "/api/v1"
 
 
@@ -107,6 +127,12 @@ app.add_middleware(
     allow_methods=["*"],
     allow_headers=["*"],
 )
+app.add_middleware(RequestContextMiddleware)
+
+# Prometheus /metrics (requests, latency, errors) — mounted at app level,
+# outside the authenticated /api/v1 prefix; scrape target for the
+# monitoring stack.
+Instrumentator().instrument(app).expose(app, endpoint="/metrics", include_in_schema=False)
 
 
 # ---------------------------------------------------------------------------
@@ -203,3 +229,55 @@ for router in ROUTERS:
 @app.get("/health", tags=["system"])
 async def health():
     return {"status": "ok", "service": "procurement-api"}
+
+
+async def _check_db() -> bool:
+    try:
+        async with AsyncSessionLocal() as session:
+            await session.execute(sql_text("SELECT 1"))
+        return True
+    except Exception:
+        logger.exception("readiness: database check failed")
+        return False
+
+
+async def _check_minio() -> bool:
+    try:
+        from app.services.storage import get_client
+
+        get_client().bucket_exists(settings.MINIO_BUCKET)
+        return True
+    except Exception:
+        logger.exception("readiness: MinIO check failed")
+        return False
+
+
+async def _check_casdoor() -> bool:
+    try:
+        async with httpx.AsyncClient(timeout=5) as client:
+            resp = await client.get(
+                settings.CASDOOR_JWKS_URL or f"{settings.CASDOOR_ENDPOINT}/.well-known/jwks"
+            )
+            return resp.status_code == 200
+    except Exception:
+        logger.exception("readiness: Casdoor JWKS check failed")
+        return False
+
+
+@app.get("/health/ready", tags=["system"])
+async def health_ready():
+    """Readiness: verifies the dependencies the API actually needs.
+
+    The deploy webhook polls this after a rebuild, so a deploy that breaks
+    the DB/MinIO/Casdoor connectivity is visible immediately.
+    """
+    checks = {
+        "database": await _check_db(),
+        "minio": await _check_minio(),
+        "casdoor": await _check_casdoor(),
+    }
+    ok = all(checks.values())
+    return JSONResponse(
+        status_code=200 if ok else 503,
+        content={"status": "ok" if ok else "degraded", "service": "procurement-api", "checks": checks},
+    )