Self-review of PR #553 surfaced five real issues — fixing them keeps
the surface honest about what's actually wired up.

- Drop dead helpers in ``context/projects.py`` (#1):
  - ``_is_eaccess`` was never called.
  - ``is_project_scope_id`` claimed to support route error formatting
    but no route used it.
  - ``_new_temp_known_projects_path`` claimed test convenience but no
    test imported it.
  - ``errno`` and ``tempfile`` imports follow.
- Drop ``ProjectScope.counts`` dataclass field (#2). Discovery never
  populated it; the route layer (``_scope_to_dict``) always overrides
  via ``_counts_for(root)``. Forward-design pollution.
- ``POST /api/context/known-projects`` now returns ``warning_code:
  "no_runtime_marker"`` alongside the prose ``warning`` (#4). Matches
  PR1's (#549) machine-readable ``reason_code`` pattern so client
  matching is i18n-stable; the prose stays for back-compat.
- ``_counts_for`` gains a cost comment (#3): 3 × (canonical scan +
  N runtime scans) per scope on every projects GET. Acceptable at
  <30 scopes; cache when discovery growth pushes that ceiling.
- JS scope badge no longer carries a redundant ``data-i18n`` attribute
  (#5). The inline ``t()`` already renders text at construction; the
  attribute would let the i18n DOM walker re-translate and clobber.
- ``ctx-scope-summary`` now carries a ``title="${scope.root}"`` (#8) so
  same-name scopes (``Edu/inflearn`` vs ``Work/inflearn``) disambiguate
  on hover without bloating the visible label.

Cache-bust: ``context-gateway.js?v=4`` → ``?v=5``.

Tests updated: ``test_post_warns_on_missing_marker`` asserts the new
``warning_code``; ``test_post_no_warning_when_marker_present`` asserts
both fields are absent. 110/110 green; ruff + format clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

…#553)

* feat(web): multi-project read-only discovery for context-gateway tabs

PR2 of the multi-project context UI series — see
``memtomem-docs/memtomem/planning/multi-project-context-ui-rfc.md``.

A user running ``mm web`` from the ``memtomem`` repo could previously
only see skills / commands / agents under that one cwd; ``~/Edu/inflearn/
.claude/skills/`` was invisible without restarting the server. PR2 adds
discovery for additional project roots (server cwd, user-registered
``known_projects.json``, opt-in ``~/.claude/projects/`` reverse-decode)
and renders one collapsible ``<details>`` group per scope inside each
tab. Mutating routes stay cwd-only — multi-scope writes ship in PR3.

Backend
-------

- ``memtomem.context.projects`` is the new discovery module:
  - ``ProjectScope`` carries ``{scope_id, label, root, tier, sources,
    missing, experimental, counts}``.
  - ``compute_scope_id`` derives ``"p-" + sha256(case-normalized
    Path.resolve())[:12]`` so refresh / restart preserve the id (RFC
    §Decision 4). On macOS the input is also lowercased: APFS is
    case-insensitive but ``Path.resolve()`` does not canonicalize case.
  - ``KnownProjectsStore`` writes ``~/.memtomem/known_projects.json``
    via ``tempfile + os.replace`` plus a ``.<name>.lock`` sidecar
    fcntl lock — locking the data file directly does not survive
    ``os.replace`` (PR #548 issue).
  - ``discover_project_scopes`` unions cwd + known-projects + (opt-in)
    claude-projects, dedupes by resolved path, and clears
    ``experimental`` on union with a trusted source.
- ``ContextGatewayConfig`` (new) carries ``known_projects_path``,
  ``experimental_claude_projects_scan: bool = False``, and
  ``user_tier_enabled: bool = False`` (forward-compat for PR3).

Routes
------

New ``web/routes/context_projects.py``:

- ``GET /api/context/projects`` — full scope list with per-type counts.
- ``POST /api/context/known-projects`` — register; absolute + ``is_dir()``
  validation; warning (HTTP 200) when no ``.claude``/``.gemini``/``.agents``/
  ``.memtomem`` marker is present so users can pre-register an empty
  checkout.
- ``DELETE /api/context/known-projects/{scope_id}`` — drop, including
  stale entries (matching is path-derived).
- ``resolve_scope_root`` is the dependency the existing
  ``/api/context/{skills,commands,agents}`` GETs now use; without
  ``?scope_id=`` it falls back to the server cwd so PR1's mutating
  cwd flow keeps working unchanged. Unknown / stale scope_id → 404.

UI
--

Each tab gains an "Add Project" button; the list area renders one
``<details class="ctx-scope-group">`` per scope, lazy-fetching items
on expand. Server CWD opens by default; non-cwd scope items render as
read-only cards (PR2 keeps mutating buttons targeting cwd only). Each
non-cwd group has an ✕ button that calls DELETE
``/api/context/known-projects/{scope_id}``.

Three new i18n keys (placeholder-form, en + ko parity).

Tests
-----

PR2 minimum-bar from RFC §Test obligations:

- ``tests/test_context_projects.py`` — scope_id stability + collision
  sanity, trailing-slash invariance, macOS case-insensitivity,
  symlink dedup, ``experimental`` flag clears on union, both
  ``experimental_claude_projects_scan`` defaults, ``known_projects.json``
  corruption / unknown-version recovery, stale-entry removal,
  multiprocessing.Process atomic-write race.
- ``tests/test_web_routes_context_projects.py`` — HTTP shape, unknown
  scope_id 404, POST 400 paths (relative / nonexistent / file),
  marker warning, idempotent registration, DELETE round-trip + 404.

Manual smoke
------------

``HOME=/tmp/.../home uv run mm web --port 8088``: GET projects shows
cwd; POST /tmp returns 200 + warning; GET projects shows two scopes
(``Server CWD`` + ``tmp``); skills?scope_id=p-bogus → 404; DELETE
round-trip works; second DELETE → 404.

Refs RFC ``multi-project-context-ui``; gates PR3 (multi-project
mutating + Claude user-tier).

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

* review fixes: drop dead helpers, add warning_code, summary tooltip

Self-review of PR #553 surfaced five real issues — fixing them keeps
the surface honest about what's actually wired up.

- Drop dead helpers in ``context/projects.py`` (#1):
  - ``_is_eaccess`` was never called.
  - ``is_project_scope_id`` claimed to support route error formatting
    but no route used it.
  - ``_new_temp_known_projects_path`` claimed test convenience but no
    test imported it.
  - ``errno`` and ``tempfile`` imports follow.
- Drop ``ProjectScope.counts`` dataclass field (#2). Discovery never
  populated it; the route layer (``_scope_to_dict``) always overrides
  via ``_counts_for(root)``. Forward-design pollution.
- ``POST /api/context/known-projects`` now returns ``warning_code:
  "no_runtime_marker"`` alongside the prose ``warning`` (#4). Matches
  PR1's (#549) machine-readable ``reason_code`` pattern so client
  matching is i18n-stable; the prose stays for back-compat.
- ``_counts_for`` gains a cost comment (#3): 3 × (canonical scan +
  N runtime scans) per scope on every projects GET. Acceptable at
  <30 scopes; cache when discovery growth pushes that ceiling.
- JS scope badge no longer carries a redundant ``data-i18n`` attribute
  (#5). The inline ``t()`` already renders text at construction; the
  attribute would let the i18n DOM walker re-translate and clobber.
- ``ctx-scope-summary`` now carries a ``title="${scope.root}"`` (#8) so
  same-name scopes (``Edu/inflearn`` vs ``Work/inflearn``) disambiguate
  on hover without bloating the visible label.

Cache-bust: ``context-gateway.js?v=4`` → ``?v=5``.

Tests updated: ``test_post_warns_on_missing_marker`` asserts the new
``warning_code``; ``test_post_no_warning_when_marker_present`` asserts
both fields are absent. 110/110 green; ruff + format clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

---------

Co-authored-by: pandas-studio <[email protected]>
Co-authored-by: Claude Opus 4.7 (1M context) <[email protected]>