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.

tests/unit/test_sync_button.py

@@ -41,6 +41,7 @@ import asyncio
 import re
 import threading
 from collections.abc import Callable, Iterator
+from datetime import datetime
 from pathlib import Path
 
 import pytest
@@ -758,6 +759,7 @@ class _GatedImport:
         progress: Callable[[str, str, int, int], None] | None = None,
         ignore_by_root: dict[str, list[str]] | None = None,  # phase 89
         include_hidden_by_root: dict[str, bool] | None = None,  # phase 105
+        doc_dates_by_root: dict[str, dict[str, datetime]] | None = None,  # phase 106
     ) -> ImportSummary:
         self.prune_flags.append(prune)
         if progress is not None: