refactor stage 1

core/schema/models/__init__.py

@@ -27,9 +27,11 @@ from .grpc import (
 )
 from .jobs import ChunkJob, ChunkJobStatus, JobStatus, TranscodeJob
 from .detect_jobs import (
-    DetectJob, DetectJobStatus, RunType, StageCheckpoint,
+    DetectJob, DetectJobStatus, RunType,
+    Timeline, Checkpoint,
     BrandSource, KnownBrand, SourceBrandSighting,
 )
+from .stages import StageConfigField, StageIO, StageDefinition, STAGE_VIEWS
 from .media import AssetStatus, MediaAsset
 from .presets import BUILTIN_PRESETS, TranscodePreset
 from .detect import DETECT_VIEWS  # noqa: F401 — discovered by modelgen generic loader
@@ -40,7 +42,8 @@ from .sources import ChunkInfo, SourceJob, SourceType
 
 # Core domain models - generates Django, SQLModel, TypeScript
 DATACLASSES = [MediaAsset, TranscodePreset, TranscodeJob, ChunkJob,
-               DetectJob, StageCheckpoint, KnownBrand, SourceBrandSighting]
+               DetectJob, Timeline, Checkpoint,
+               KnownBrand, SourceBrandSighting]
 
 # API request/response models - generates TypeScript only (no Django)
 # WorkerStatus from grpc.py is reused here