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

schema/modelgen.json

@@ -6,16 +6,6 @@
       "output": "mpr/media_assets/models.py",
       "include": ["dataclasses", "enums"]
     },
-    {
-      "target": "pydantic",
-      "output": "api/schema/",
-      "include": ["dataclasses", "enums"],
-      "name_map": {
-        "TranscodeJob": "Job",
-        "MediaAsset": "Asset",
-        "TranscodePreset": "Preset"
-      }
-    },
     {
       "target": "graphene",
       "output": "api/schema/graphql.py",

schema/models/__init__.py

@@ -5,7 +5,13 @@ This module exports all dataclasses, enums, and constants that the generator
 should process. Add new models here to have them included in generation.
 """
 
-from .api import CreateJobRequest, ScanResult, SystemStatus
+from .api import (
+    CreateJobRequest,
+    DeleteResult,
+    ScanResult,
+    SystemStatus,
+    UpdateAssetRequest,
+)
 from .grpc import (
     GRPC_SERVICE,
     CancelRequest,
@@ -26,7 +32,14 @@ DATACLASSES = [MediaAsset, TranscodePreset, TranscodeJob]
 
 # API request/response models - generates TypeScript only (no Django)
 # WorkerStatus from grpc.py is reused here
-API_MODELS = [CreateJobRequest, SystemStatus, ScanResult, WorkerStatus]
+API_MODELS = [
+    CreateJobRequest,
+    UpdateAssetRequest,
+    SystemStatus,
+    ScanResult,
+    DeleteResult,
+    WorkerStatus,
+]
 
 # Status enums - included in generated code
 ENUMS = [AssetStatus, JobStatus]
@@ -50,6 +63,8 @@ __all__ = [
     "TranscodeJob",
     # API Models
     "CreateJobRequest",
+    "UpdateAssetRequest",
+    "DeleteResult",
     "ScanResult",
     "SystemStatus",
     # Enums

schema/models/api.py

@@ -40,4 +40,19 @@ class ScanResult:
     files: List[str] = field(default_factory=list)
 
 
+@dataclass
+class UpdateAssetRequest:
+    """Request body for updating asset metadata."""
+
+    comments: Optional[str] = None
+    tags: Optional[List[str]] = None
+
+
+@dataclass
+class DeleteResult:
+    """Result of a delete operation."""
+
+    ok: bool = False
+
+
 # Note: WorkerStatus is defined in grpc.py and reused here