refactor(dolt): pass run_id to SourceImporter.promote

Both real target tables (fundamental_snapshots, earnings_events) carry an
import_run_id; stamping requires the current run's id. A2 (the earnings
importer) is the first real consumer, so promote gains a run_id argument rather
than having importers hack the running row out of the framework. Protocol +
call site updated; the A1 fake importer now stamps and asserts import_run_id.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/services/data_import.py

@@ -94,9 +94,11 @@ class SourceImporter(Protocol):
         """Run the source's validation gates against ``staged``. Read-only."""
         ...
 
-    async def promote(self, db: AsyncSession, staged: Any) -> dict[str, int]:
+    async def promote(self, db: AsyncSession, staged: Any, run_id: int) -> dict[str, int]:
         """Apply ``staged`` to the live tables. Called inside the promotion
-        transaction; the caller commits. Returns row-count deltas."""
+        transaction; the caller commits. ``run_id`` is the current
+        ``data_import_runs.id`` so written rows can be stamped with their
+        ``import_run_id``. Returns row-count deltas."""
         ...
 
 
@@ -213,7 +215,7 @@ async def run_import(
                     return run
 
                 # Promotion: importer writes + run-row flip in one transaction.
-                row_counts = await importer.promote(session, staged)
+                row_counts = await importer.promote(session, staged, run.id)
                 run.status = STATUS_PROMOTED
                 run.row_counts_json = json.dumps(row_counts, default=str)
                 run.completed_at = _now()