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/models.py

@@ -110,6 +110,27 @@ class Document(Base):
     content: Mapped[str] = mapped_column(Text)  # full markdown — the RAG context
     content_hash: Mapped[str] = mapped_column(String(64), index=True)  # sha256 for change detection
     indexed_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    #: The document's CREATION date (phase 106, D1/D2/D3) — sourced at
+    #: sync time (git last-commit date for git sources, file mtime for
+    #: local dirs / unpacked uploads), normalized by
+    #: :func:`app.rag.doc_dates.normalize_doc_date` (undetermined or
+    #: future → today; UTC). NOT NULL: pre-phase-106 rows backfill to
+    #: the migration moment (≈ today — the owner's instruction) and the
+    #: next sync refreshes them (the importer's unchanged path,
+    #: task 04 — a sync may move a date OLDER, D4). Distinct from
+    #: ``indexed_at`` (the INDEX time, untouched).
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+    #: True only while ``created_at`` is the OWNER'S correction (phase
+    #: 106, D1 — the ``folder_summaries.manually_edited`` phase-97
+    #: precedent): set ONLY by ``PATCH /api/documents/date``
+    #: (task 05); the sync-time importer SKIPS the refresh on a manual
+    #: row (the correction survives syncs, D4) and a content change
+    #: RESETS both the date and the flag (a new version = a new date).
+    created_at_manual: Mapped[bool] = mapped_column(
+        Boolean, default=False, server_default=text("false"), nullable=False
+    )
     #: Lite-model summary, phase 30. Natural-language summary of the
     #: document (non-markdown A9 docs only, generated at import time by the
     #: aipi ``lite`` model). NULL for markdown docs, pre-phase-30 rows, and