docs: add maintenance mode + TFE visibility tasks to TODO

TODO.md

@@ -203,6 +203,120 @@ These must remain unbroken after the tag-management UI is live:
 - [ ] `storage/fixtures/CreateTestDatabase.php`: update to use `tags` / `thesis_tags`
       table names and `findOrCreateTag()`
 
+## Feature: Mode Maintenance
+
+Adds "Déployer" / "Maintenance" buttons in admin. When maintenance mode is on,
+the public site is unavailable (503) while the admin section keeps working.
+
+### Implementation
+
+- [ ] **Storage** — store maintenance flag as a file on disk (`storage/maintenance.flag`)
+      so it requires no DB and survives restarts; flag presence = maintenance mode ON
+- [ ] **Public gate** — add a check at the top of every public-facing PHP entry-point
+      (`public/index.php`, `public/search.php`, `public/tfe.php`, `public/media.php`,
+      `public/apropos.php`) via a shared helper in `config/bootstrap.php`:
+      `checkMaintenanceMode()` — if flag exists, render a 503 maintenance page and exit
+- [ ] **Maintenance page** — create `public/maintenance.php` (503 HTML page, styled
+      minimally, not imported via bootstrap so it never recurses)
+- [ ] **Admin action** — create `public/admin/actions/maintenance.php` (POST handler):
+      CSRF-validated, two actions: `enable` (touch flag file) and `disable` (unlink flag)
+- [ ] **Admin UI** — add a "Site en ligne / Maintenance" status bar in
+      `public/admin/index.php` with "Déployer" (→ disable) and "Maintenance" (→ enable)
+      buttons; display current state clearly (green = en ligne, orange = maintenance)
+- [ ] **Admin exemption** — admin pages (`/admin/*`) must NOT be gated; the maintenance
+      check must only run on public routes; admin bootstrap already bypasses it by
+      not calling `checkMaintenanceMode()`
+- [ ] **`src/config.php`** — add `MAINTENANCE_FLAG_PATH` constant pointing to
+      `storage/maintenance.flag`
+
+## Feature: TFE Visibility States (publique / interne / interdit)
+
+Replaces the binary `is_published` with a three-state `visibility` field on each TFE,
+controlling what the public site exposes. Default: `interne`.
+
+### States
+
+| State      | DB value | Public page: metadata | Public page: files | Note displayed |
+|------------|----------|-----------------------|--------------------|----------------|
+| `publique` | `public` | ✓ full                | ✓ via media.php    | —              |
+| `interne`  | `intern` | ✓ full                | ✗ hidden           | "Copies physiques disponibles aux archives de l'école." |
+| `interdit` | `forbid` | ✓ full                | ✗ hidden           | `context_note` from DB (jury note, editable in admin) |
+
+### Schema
+
+- [ ] **DB migration** — `storage/migrations/002_add_visibility.sql`:
+      - `ALTER TABLE theses ADD COLUMN visibility TEXT NOT NULL DEFAULT 'intern'`
+      - `UPDATE theses SET visibility = 'public' WHERE is_published = 1` (migrate existing data)
+      - update `v_theses_full` view to expose `visibility` (DROP + CREATE in migration)
+      - update `v_theses_public` view: change filter from `is_published = 1` to
+        `is_published = 1` (keep; `is_published` stays for "show in listings" gate)
+      - **Note**: `is_published` keeps its meaning (appears in public listings at all);
+        `visibility` controls *what* is accessible once found; a TFE can be
+        `is_published = 1` + `visibility = 'intern'` → appears in list, files hidden
+- [ ] **`storage/schema.sql`** — add `visibility` column + update views + add
+      `idx_theses_visibility` index
+- [ ] **`storage/fixtures/CreateTestDatabase.php`** — seed some TFEs with each visibility
+      state (default: `intern`)
+
+### Backend
+
+- [ ] **`src/Database.php`**:
+      - `getThesisById($id)` — already used by `tfe.php`; ensure it returns `visibility`
+        and `context_note`
+      - `getThesis($id)` (admin) — already returns all columns; ensure `visibility` and
+        `context_note` pass through
+      - `getThesesList()` — add `visibility` to SELECT for admin list display
+      - `setVisibility(int $thesisId, string $state): void` — UPDATE
+        `theses SET visibility = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?`;
+        validate `$state` ∈ `['public', 'intern', 'forbid']`
+      - `bulkSetVisibility(array $ids, string $state): void` — batch UPDATE for the
+        bulk-action bar
+
+### Public site
+
+- [ ] **`public/media.php`** — add visibility check:
+      1. Load `thesis_files` row by `path` to get `thesis_id`
+      2. Load `theses.visibility` for that `thesis_id` (one extra query)
+      3. If `visibility !== 'public'` → return 403
+      (This is the critical security gate; all other changes are UX)
+- [ ] **`public/tfe.php`** — conditional rendering based on `$data['visibility']`:
+      - `publique`: render files normally (existing logic)
+      - `interne`: skip files block; show notice "Les copies physiques de ce travail
+        sont disponibles dans les archives de l'école."
+      - `interdit`: skip files block; show `$data['context_note']` (jury note) if set,
+        otherwise a generic access-restricted message
+- [ ] **`public/index.php`** / **`public/search.php`** — no change needed (thumbnail
+      logic: if `visibility !== 'public'`, skip thumbnail even if file exists; adjust
+      the thumbnail-lookup block in index.php)
+
+### Admin UI
+
+- [ ] **`public/admin/edit.php`**:
+      - Replace the current `is_published` checkbox with a `<select name="visibility">`
+        with three labelled options (Publique / Interne / Interdit)
+      - Keep `is_published` checkbox separately (controls listing visibility)
+      - Add `<textarea name="context_note">` for jury note (shown only when
+        `visibility = interdit`, via JS toggle, but always submitted so admin can
+        pre-fill before switching state)
+      - Update the POST handler to save `visibility` and `context_note` via
+        `UPDATE theses SET visibility = ?, context_note = ? …`
+- [ ] **`public/admin/index.php`**:
+      - Update status badge column: show three-state badge instead of binary
+        "Publié / En attente":
+        - `publique` → green "Publique"
+        - `interne` → blue "Interne"
+        - `interdit` → red "Interdit"
+      - Update stats bar: counts for each state instead of published/pending
+      - Add bulk-action buttons for visibility: "Rendre publique", "Rendre interne",
+        "Rendre interdit" (replaces or supplements existing publish/unpublish)
+      - Update JS `bulkAction()` to support new action names
+- [ ] **`public/admin/actions/publish.php`** — extend to handle new visibility actions:
+      `set_public`, `set_intern`, `set_forbid` for single and bulk modes;
+      keep existing `publish`/`unpublish` actions for `is_published` toggle;
+      alternatively rename/create `public/admin/actions/visibility.php` as a
+      dedicated handler and keep `publish.php` for `is_published` only
+- [ ] **`public/admin/thanks.php`** — add "Visibilité" row to the info display
+
 ## Pending
 
 - [x] Add flake.nix for Nix-based PHP dev environment