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/rag/prompts.py

@@ -352,6 +352,12 @@ source-name ``ls`` scope, the combined ``source/path`` identity for
     cap — not the prompt — decides whether the tools are actually
     offered to the model, see :mod:`app.rag.agent`).
 
+    Each ``<document>`` block carries the identity attributes
+    ``source`` / ``path`` / ``title`` — and, since phase 106 (D5),
+    ``date`` (the row's ``created_at`` UTC date part, ``YYYY-MM-DD``,
+    APPENDED after ``title`` — the only position; always present,
+    ``created_at`` is NOT NULL) — plus the document's full text.
+
     Gate-iteration note (task 05, 2026-09-03/04): an in-context reminder
     LEADING this section (the document texts are already context — do
     not ``read`` one the user asked to open) was tried and REVERTED:
@@ -368,8 +374,13 @@ source-name ``ls`` scope, the combined ``source/path`` identity for
     # attribute at the ``source``/``path`` copy site was TRIED and
     # REVERTED the same day (no improvement across runs; the block stays
     # exactly the document identity + full text).
+    # Phase 106 (D5): every document the model sees carries its
+    # creation date — the block's ``date`` attribute (the row's
+    # ``created_at`` UTC date part, appended after ``title`` — the
+    # only position; always present, ``created_at`` is NOT NULL).
     blocks = [
-        f'<document source="{doc.source}" path="{doc.path}" title="{doc.title}">\n'
+        f'<document source="{doc.source}" path="{doc.path}" title="{doc.title}" '
+        f'date="{doc.created_at:%Y-%m-%d}">\n'
         f"{doc.content}\n"
         "</document>"
         for doc in documents