feat(api): add import job REST API and service layer

Add REST API endpoints and business logic for GEDCOM import job management:

API Endpoints (6):
- POST /api/import-jobs - Create job with file upload
- GET /api/import-jobs - List user's jobs (paginated, filterable)
- GET /api/import-jobs/{job_id} - Get job detail with stages
- POST /api/import-jobs/{job_id}/pause - Pause running job
- POST /api/import-jobs/{job_id}/resume - Resume paused job
- DELETE /api/import-jobs/{job_id} - Cancel job and delete files

Service Layer:
- create_import_job() - Upload GEDCOM, transition UPLOADED → QUEUED
- get_job_with_stages() - Fetch job with pipeline stages
- list_user_jobs() - Paginated job list with filtering
- pause_job() / resume_job() - Job lifecycle management
- cancel_job() - Delete job and cleanup storage
- claim_next_job() - Worker job claiming (lease-based)
- complete_stage() / fail_job() - Stage execution updates

Database Changes:
- Add order field to ImportJobStage for pipeline ordering
- Change ImportJob.user_id from UUID to string (for Google JWT subject IDs)

Tests:
- 17 comprehensive endpoint tests (100% passing)
- Coverage: routes 72%, service layer 26% (worker functions untested)

File Storage:
- Pattern: /data/gedcom/{user_id}/{job_id}/original.ged
- user_id is string (Google subject), job_id is UUID

State Machine:
- Jobs: UPLOADED → QUEUED → IN_PROGRESS → PAUSED/COMPLETED/FAILED/CANCELLED
- Stages: PENDING → IN_PROGRESS → COMPLETED/FAILED/RETRYING

Author: sjlangley

apps/api/src/api/app.py

@@ -13,7 +13,7 @@
 import api.database  # noqa: F401 - Import to register models with SQLModel metadata
 from api.enums import Environment
 from api.logging import setup_logging
-from api.routes import auth, health, user, wikitree
+from api.routes import auth, health, import_jobs, user, wikitree
 from api.settings import Settings, settings
 
 logger = logging.getLogger(__name__)
@@ -148,5 +148,6 @@ async def lifespan(application: FastAPI):
 
 app.include_router(auth.router, prefix='/auth')
 app.include_router(health.router, prefix='/health')
+app.include_router(import_jobs.router, prefix='/api')
 app.include_router(user.router, prefix='/user')
 app.include_router(wikitree.router, prefix='/api')

apps/api/src/api/database.py

@@ -68,7 +68,9 @@ class ImportJob(SQLModel, table=True):
     __tablename__ = 'import_jobs'  # pyrefly: ignore[bad-override]
 
     id: UUID = Field(default_factory=uuid4, primary_key=True)
-    user_id: UUID = Field(foreign_key='app_users.id', index=True)
+    # user_id stores Google subject ID directly (not FK to app_users)
+    # because auth uses JWT validation, not database user lookups
+    user_id: str = Field(index=True)
     source_type: str  # gedcom | wikitree-export | manual
     original_filename: str
     stored_path: str
@@ -93,7 +95,8 @@ class ImportJobStage(SQLModel, table=True):
 
     id: UUID = Field(default_factory=uuid4, primary_key=True)
     import_job_id: UUID = Field(foreign_key='import_jobs.id', index=True)
-    stage_name: str  # parse | normalize | search | match | review
+    stage_name: str  # validate | parse | normalize | search | match | review
+    order: int  # Pipeline execution order (0=validate, 1=parse, etc.)
     status: ImportJobStageStatus = Field(
         sa_column=Column(
             SQLEnum(ImportJobStageStatus), index=True, nullable=False