perf(observatory): pack camera epoch source transfer

src/k1link/web/observatory_worker_api.py

@@ -26,6 +26,8 @@ from pydantic import BaseModel, ConfigDict, Field
 
 from k1link.observatory.portable_artifact_transport import (
     MAX_RESULT_MANIFEST_BYTES,
+    PORTABLE_CAMERA_EPOCH_ARCHIVE_ID_HEADER,
+    PORTABLE_CAMERA_EPOCH_ARCHIVE_MEDIA_TYPE,
     PortableArtifactTransportError,
     PortableArtifactTransportIntegrityError,
     PortableArtifactTransportUnavailableError,
@@ -381,6 +383,41 @@ def build_observatory_worker_router(
                 .as_dict()
             )
 
+        @router.get("/recorded-jobs/{job_id}/source-camera-epoch-archive")
+        def source_camera_epoch_archive(
+            job_id: Annotated[str, ApiPath(pattern=_JOB_ID_PATTERN)],
+            claim_token: Annotated[
+                str,
+                Header(
+                    alias=OBSERVATORY_WORKER_CLAIM_TOKEN_HEADER,
+                    pattern=_CLAIM_TOKEN_PATTERN,
+                ),
+            ],
+            claim_generation: Annotated[
+                int,
+                Header(alias=OBSERVATORY_WORKER_CLAIM_GENERATION_HEADER, ge=1),
+            ],
+        ) -> FileResponse:
+            archive, path = _artifact_call(
+                lambda: artifact_transport.materialize_camera_epoch_archive(
+                    job_id=job_id,
+                    claim_token=claim_token,
+                    claim_generation=claim_generation,
+                    claimant_id=authentication.contour_id,
+                )
+            )
+            return FileResponse(
+                path,
+                media_type=PORTABLE_CAMERA_EPOCH_ARCHIVE_MEDIA_TYPE,
+                headers={
+                    "ETag": f'"{archive.sha256}"',
+                    "Cache-Control": "private, no-store",
+                    "X-Content-Type-Options": "nosniff",
+                    "X-Mission-Core-Content-Sha256": archive.sha256,
+                    PORTABLE_CAMERA_EPOCH_ARCHIVE_ID_HEADER: archive.archive_id,
+                },
+            )
+
         @router.get("/recorded-jobs/{job_id}/source-members/{member_id}")
         def source_member(
             job_id: Annotated[str, ApiPath(pattern=_JOB_ID_PATTERN)],