refactor(agents): migrate .agent/ planning tree to .agents/

Standardize on the .agents/ directory (shared with project skills):
phases/, user_stories/, reports/, screenshots/, validate.sh, and
phase-sessions/ + pipeline.log all move to .agents/ (git mv preserves
history; runtime artifacts move alongside).

Updates every reference in AGENTS.md, README.md, .gitignore, app
docstrings, and test story headers. Historical KB content in data/
and the runtime pipeline.log transcript are left untouched.

.agents/user_stories/local-directory-sources.md

@@ -0,0 +1,49 @@
+# Story: Local directory sources
+
+**Phase:** `38_local_directory_sources` · **E2E:** `tests/e2e/test_local_directory_sources.py`
+
+## Narrative
+
+As **the admin (owner)**, some of my documents live in plain directories
+that are **not git repos** — today the only way to index them is the CLI's
+`--source` flag, which the web app's Sync path ignores. I want to **add an
+existing local directory as a source** from the same admin page as the git
+sources, and have the Sync button and `import_docs` import it alongside the
+git checkouts.
+
+- **Given** I am signed in as admin, and `~/Notes` is a plain (non-git)
+  directory
+- **When** I add it on the sources page and click Sync
+- **Then** the directory is walked and imported together with the git
+  checkouts in one run (pruning over the union), and a missing directory
+  fails the run loudly instead of importing a partial KB.
+
+## Acceptance criteria
+1. Migration 0007: `git_sources.kind TEXT NOT NULL DEFAULT 'git'` (check:
+   `git`|`local`) + `git_sources.path TEXT NULL` (unique; non-null only for
+   local) — reversible, up/down integration-tested (the 0004–0006 pattern).
+2. The admin API (phase 35) accepts `kind`: `git` rows validate `url`
+   exactly as today; `local` rows require `path` (trimmed, expanded,
+   absolute, existing directory on the server → else 422 naming the path);
+   409 on duplicate (per kind); GET rows carry `kind` + `path` (env
+   fallback rows are git-only).
+3. The sync pipeline and `import_docs` resolve DB **git + local** rows
+   together (git → clone/pull; local → direct directory walk; a missing
+   local dir aborts the run before importing, with the path named);
+   `--source` still wins; `BOR_GIT_SOURCES` stays a git-only fallback;
+   both-empty fails loudly ("no sources configured").
+4. The page: a second "Local directory" add form (labeled path input,
+   inline error, never-stale button per §7.4); list rows show a kind badge
+   (Git/Local, distinguishable by more than color); the hint says Sync
+   imports git checkouts and local directories together (union prune).
+5. README: the two source types + add-time validation + "the DB is the
+   local-source registry"; no new env var.
+6. Unit + integration green, `app/` coverage >90%, story E2E green in
+   isolation, ruff + pyright clean, one `--no-gpg-sign` commit.
+
+## Playwright Mapping Rule
+`tests/e2e/test_local_directory_sources.py` — one story, one file, run in
+isolation: the admin adds a temp local directory → it appears with the
+Local badge; a missing path gets an inline error; Sync imports its fixture
+file (visible via `GET /api/docs`); deleting the file and syncing again
+prunes it; removing the row removes it from the list.