phase: 106_document_dates

Everything is verified green. Final report:

**Phase 106 — Document dates (final verification pass; all 10 tasks already complete)**

- Verified all phase artifacts: alembic `0020` (dev DB at `0020`), `doc_dates.py`, git `file_commit_dates`, importer `doc_dates_by_root`/`dates_updated`, both entry-point wirings, date APIs + tree `created_at`/`updated_at`, LLM surfaces (prompt block, `read` line 2, appended `ls` field), `apply_recency_boost` in `retrieve()`, UI columns/badge, admin editor, mock-LLM regex — all present and correct; no defects found, no fixes needed.
- `uv run pytest --cov=app --cov-report=term-missing` → **2299 passed, TOTAL 99%** (>90% ✓)
- `uv run pytest tests/e2e/test_document_dates.py -v --no-cov` → **6/6 passed** in isolation (DB up)
- 12 regression E2E suites (retrieval_quality, whole_document_context, agent_document_tools, ls_tree_drilldown, read_truncation_cap, kb_tree, kb_tree_nav, document_viewer, edit_summaries, import_documents, sync_button, hidden_folders_toggle, smoke) → **all green in isolation**
- `uv run ruff check .` → clean; `uv run pyright` → **0 errors, 0 warnings**

**Completion criteria:** 1) non-null `created_at` + 0020 upgrade/downgrade on dev DB ✓ (real-Alembic integration tests) 2) sync refresh/older/manual-persists/content-reset/no sources_meta bump ✓ 3) zip/tar mtime + future→today ✓ 4) LLM date surfaces + cross-check ✓ 5) UI Created/Updated/badge positions ✓ 6) admin editor set+revert round-trip ✓ 7) old-correct-beats-new-similar (defaults & boost-off) + near-tie + `BOR_RECENCY_BOOST=0` byte-identical ✓ 8) full gate ✓ 9) commit/phase-move — left to harness per instructions.

- **Notable:** recency default tuned 0.001 → **0.0007** (task 07 step 5 explicitly permits; measured margins recorded in `test_recency_boost.py` docstring).
- **Next pending phase:** none — `todo/` holds only this phase.

app/api/sync.py

@@ -36,9 +36,13 @@ decisions):
 4. ``import_sources(..., prune=True)`` over the single combined list
    (git checkouts + local dirs), honoring each row's ``ignore_paths``
    (phase 89 — the per-root ignore map is built in the same per-row
-   loop as the source list) and its ``include_hidden`` flag (phase 105
-   — the per-root hidden-folders map, same per-row construction) —
-   prune so files deleted upstream, out of
+   loop as the source list), its ``include_hidden`` flag (phase 105 —
+   the per-root hidden-folders map, same per-row construction), and
+   feeding each git checkout's per-file last-commit dates (phase 106,
+   D2 — the per-root date map, ``file_commit_dates`` after the clone,
+   same per-row construction; local rows contribute nothing and take
+   the importer's mtime fallback) — prune so files deleted upstream,
+   out of
    a local dir, or newly matching an ignore pattern leave the index
    (pruning covers the union; the CLI's no-prune default is unchanged);
 5. when the import changed the KB (added + updated > 0),
@@ -117,7 +121,7 @@ from app.rag.importer import ImportSummary, import_sources
 from app.rag.llm import LLMClient, check_models
 from app.rag.overview import regenerate_overview
 from app.rag.sources_meta import bump_sources_version, current_sources_version
-from scripts.git_sync import GitSyncError, clone_or_pull
+from scripts.git_sync import GitSyncError, clone_or_pull, file_commit_dates
 from scripts.import_docs import repo_name
 
 logger = logging.getLogger("app.api.sync")
@@ -286,9 +290,17 @@ async def _run_sync() -> None:
         sources: list[Path] = []
         ignore_by_root: dict[str, list[str]] = {}
         include_hidden_by_root: dict[str, bool] = {}
+        doc_dates_by_root: dict[str, dict[str, datetime]] = {}
         for row in rows:
             if row.kind == "git":
                 root = clone_or_pull(row.url, sources_root / repo_name(row.url))
+                # Phase 106 (D2): the checkout's per-file last-commit
+                # dates, keyed by the SAME root string the importer
+                # sees (local-path checkouts → true per-file dates,
+                # shallow URL checkouts → the tip date, D10). Local
+                # rows contribute nothing — the importer's mtime
+                # fallback applies to them.
+                doc_dates_by_root[str(root)] = file_commit_dates(root)
             else:
                 # kind=local — the stored expanded path (phase 38 also
                 # mirrors it in the NOT-NULL ``url`` location column, the
@@ -329,6 +341,7 @@ async def _run_sync() -> None:
         summary: ImportSummary = await import_sources(
             sources, llm, prune=True, progress=_hook, ignore_by_root=ignore_by_root,
             include_hidden_by_root=include_hidden_by_root,
+            doc_dates_by_root=doc_dates_by_root,
         )
         overview = False
         if summary.added + summary.updated > 0:
@@ -431,6 +444,7 @@ async def _run_sync() -> None:
             "chunks": summary.chunks,
             "summaries": summary.summaries,
             "summary_errors": summary.summary_errors,
+            "dates_updated": summary.dates_updated,
             "overview": overview,
             "sources_version": sources_version,
         }