Remove REST API, keep GraphQL as sole API

- Add missing GraphQL mutations: retryJob, updateAsset, deleteAsset
- Add UpdateAssetRequest and DeleteResult to schema source of truth
- Move Lambda callback endpoint to main.py (only REST endpoint)
- Remove REST routes, pydantic schemas, and deps
- Remove pydantic target from modelgen.json
- Update architecture diagrams and documentation

api/main.py

@@ -1,11 +1,13 @@
 """
 MPR FastAPI Application
 
-Main entry point for the REST API.
+Serves GraphQL API and Lambda callback endpoint.
 """
 
 import os
 import sys
+from typing import Optional
+from uuid import UUID
 
 # Add project root to path
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
@@ -17,16 +19,17 @@ import django
 
 django.setup()
 
-from fastapi import FastAPI
+from fastapi import FastAPI, Header, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
+from starlette_graphene3 import GraphQLApp, make_graphiql_handler
 
 from api.graphql import schema as graphql_schema
-from api.routes import assets_router, jobs_router, presets_router, system_router
-from starlette_graphene3 import GraphQLApp, make_graphiql_handler
+
+CALLBACK_API_KEY = os.environ.get("CALLBACK_API_KEY", "")
 
 app = FastAPI(
     title="MPR API",
-    description="Media Processor REST API",
+    description="Media Processor — GraphQL API",
     version="0.1.0",
     docs_url="/docs",
     redoc_url="/redoc",
@@ -41,12 +44,6 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-# Routes - all under /api prefix
-app.include_router(system_router, prefix="/api")
-app.include_router(assets_router, prefix="/api")
-app.include_router(presets_router, prefix="/api")
-app.include_router(jobs_router, prefix="/api")
-
 # GraphQL
 app.mount("/graphql", GraphQLApp(schema=graphql_schema, on_get=make_graphiql_handler()))
 
@@ -57,5 +54,45 @@ def root():
     return {
         "name": "MPR API",
         "version": "0.1.0",
-        "docs": "/docs",
+        "graphql": "/graphql",
     }
+
+
+@app.post("/api/jobs/{job_id}/callback")
+def job_callback(
+    job_id: UUID,
+    payload: dict,
+    x_api_key: Optional[str] = Header(None),
+):
+    """
+    Callback endpoint for Lambda to report job completion.
+    Protected by API key.
+    """
+    if CALLBACK_API_KEY and x_api_key != CALLBACK_API_KEY:
+        raise HTTPException(status_code=403, detail="Invalid API key")
+
+    from django.utils import timezone
+
+    from mpr.media_assets.models import TranscodeJob
+
+    try:
+        job = TranscodeJob.objects.get(id=job_id)
+    except TranscodeJob.DoesNotExist:
+        raise HTTPException(status_code=404, detail="Job not found")
+
+    status = payload.get("status", "failed")
+    job.status = status
+    job.progress = 100.0 if status == "completed" else job.progress
+    update_fields = ["status", "progress"]
+
+    if payload.get("error"):
+        job.error_message = payload["error"]
+        update_fields.append("error_message")
+
+    if status in ("completed", "failed"):
+        job.completed_at = timezone.now()
+        update_fields.append("completed_at")
+
+    job.save(update_fields=update_fields)
+
+    return {"ok": True}