phase: 190_app_name_settings_fix

All gates re-verified green. Report:

- **Verified (all 4 tasks already complete; this was the final pass):** `effective_settings` resolves the 3 brand strings panel-row → tab-row → env (`applied_override_keys`, presence-not-value); `PUT /api/ui-settings` ignores string body fields; Theme-tab form is colors-only (17 pickers, no `#theme-app-name`/`#theme-placeholder`/`#theme-footer`); the ONE shared `applyBrandFromConfig` re-applies title/`.brand-text`/footer/placeholder after a panel save-reset and a tab save-reset; boot path byte-identical (single `/api/config`).
- **Completion criteria:**
  - strings order panel→tab→env, both branches — ✅ `tests/unit/test_theming.py::test_effective_app_name_prefers_settings_panel_row_over_ui_settings_row`, `..._fall_back_to_ui_settings_row_without_panel_row`, `..._per_field_panel_then_tab_then_env`, `..._ignore_panel_rows_when_the_overlay_is_off`
  - PUT ignores string fields + no 3 inputs in the tab — ✅ `tests/integration/test_ui_settings_api.py::test_put_ignores_string_fields_in_body` (+2) and the E2E `test_theme_tab_dom_is_colors_only`
  - live apply without reload + incident regression — ✅ `tests/e2e/test_app_name_settings_fix.py` tests 1–4
  - byte-identical boot, no double-apply — ✅ `tests/unit/test_brand_live.py` markers + E2E "exactly one /api/config"
  - suite green, coverage >90%, ruff+pyright clean — ✅
  - no behavior change in prior phases — ✅ (palette, phase-168 panel, env fallback suites all green)
  - atomic commit — **left to the harness** (pipeline rule overrides per-phase committing; no git write run)
- **Gates:** `uv run pytest --cov=app --cov-report=term-missing` → **4630 passed, TOTAL 6941 16 99%**, exit 0 · `uv run pytest tests/e2e/test_app_name_settings_fix.py -v --no-cov` → **6 passed** in isolation · regression E2E (isolated, one process each, all exit 0): `test_smoke` `test_configurable_brand` `test_admin_theme_tab` `test_theme_save_and_coverage` `test_theme_semantic_completion` `test_themed_favicon` `test_dark_tech_theme` `test_admin_settings_panel` `test_admin_settings_layout` `test_settings_mobile_value_width` · `uv run ruff check .` → All checks passed · `uv run pyright` → 0 errors.
- **Documentation:** README — fixed "saving one repaints *every* open page" (only the open document repaints; other pages on next load) and a broken paragraph wrap in *Customizing the look*; AGENTS.md rule 16 — `test_chunks_hnsw_recall.py` now described accurately (index paths forced with `enable_seqscan`/`indexonlyscan`/`bitmapscan` off, unforced plan asserted only on a pristine relation); `tests/unit/test_theme_frontend.py` — two stale section headers ("20 form fields"/"20 inputs" → 17 color). No AGENTS.md settings-overlay/resolution-order clause exists, so per the phase none was added. Full env-var cross-check (`BOR_*` in `app/config.py` vs README) → 0 gaps; 0 missing file references.
- **Notable:** the working tree also carries this phase's flake hardening of the phase-188 `tests/integration/test_chunks_hnsw_recall.py` (verified legit and green). Live infra untouched; shared DB left clean (0 `app_settings`, 0 `ui_settings`). **Flagged, not changed:** `settings_overlay.applied_override_keys` lets a `ProgrammingError` (missing `app_settings`) propagate from public `GET /api/config`, where `load_overrides` deliberately fails soft — only reachable on an un-migrated (0027) DB, outside this phase's pinned A1 semantics, so left for the owner to rule on rather than silently deviating.
- **Next pending phase:** `191_source_name_labels_tags`.

frontend/assets/settings.js

@@ -75,6 +75,18 @@
  *     button, Escape / No cancels) → DELETE /api/admin/settings →
  *     the status line `Cleared N overrides.` (N from the
  *     response) + a re-GET.
+ *   • the live brand re-apply (phase 190, task 03 — A2, the second half
+ *     of "takes effect on clicking save") — when a save / Reset / Clear
+ *     all touched one of the three brand strings (`app_name`,
+ *     `input_placeholder`, `footer_text` — the panel's own keys), the
+ *     OPEN document is re-branded from a fresh `GET /api/config`
+ *     through `window.applyBrandFromConfig` (the ONE pass brand.js owns
+ *     and the boot runs — this file never writes the title / brand /
+ *     footer / placeholder itself). No brand key in the batch → no
+ *     extra request; a failed re-apply leaves the document exactly as
+ *     it was (never a blanked brand); the catalogue re-GET stays the
+ *     catalogue's own refresh. The Theme tab (theme.js) runs the SAME
+ *     shared pass after its own save / reset.
  *   • search — #settings-filter: a case-insensitive substring over
  *     the label + BOR_* name cells, applied on input with NO fetch
  *     (the phase-101 tokens D4 contract) and RE-APPLIED after every
@@ -447,6 +459,48 @@ export async function mount(root) {
     }
   }
 
+  /* ---------- the live brand re-apply (phase 190, task 03 — A2) ----------
+   * The phase-168 header contract is "the change should take effect on
+   * clicking 'save'" — for the three BRAND strings that means the OPEN
+   * document too, not just the catalogue. One pass, ONE owner:
+   * brand.js exports the boot's own function as
+   * window.applyBrandFromConfig, and this helper feeds it a fresh
+   * GET /api/config (the same no-store request the boot makes).
+   *
+   *   • gated on the key — a save / Reset of any of the ~72 other rows
+   *     costs NO extra request and no DOM churn; Clear all passes all
+   *     three because clearing hands every one of them back to the
+   *     Theme-tab row or the environment;
+   *   • the §7.4 guard, EXTENDED not forked — the save itself is already
+   *     inside `saveInFlight` (this helper is awaited before that flag
+   *     drops, so a second Save can never start mid-re-apply) and the
+   *     one flag below covers the settle paths that share the pass, so a
+   *     second save / Reset / Clear all never stacks a second fetch;
+   *   • never a blanked brand — a non-2xx or an unreachable app returns
+   *     WITHOUT touching the DOM (the phase-168 "never a blanked panel"
+   *     precedent): the open page keeps its last applied name, footer
+   *     and placeholder, and the save's own status / error line stays
+   *     the visibility. */
+  const BRAND_KEYS = ["app_name", "input_placeholder", "footer_text"];
+  let brandReapplyInFlight = false;
+
+  async function reapplyBrand(keys) {
+    if (!keys.some((key) => BRAND_KEYS.includes(key))) return; // not a brand row
+    if (brandReapplyInFlight) return; // one re-apply at a time (§7.4)
+    if (typeof window.applyBrandFromConfig !== "function") return; // brand.js is the owner
+    brandReapplyInFlight = true;
+    try {
+      const r = await fetch("/api/config", { cache: "no-store" });
+      if (!r.ok) return; // the brand keeps its last applied state
+      window.applyBrandFromConfig(await r.json());
+    } catch {
+      /* unreachable app or a non-JSON body — nothing is written (the
+         brand never blanks; the settle path's own line says it) */
+    } finally {
+      brandReapplyInFlight = false;
+    }
+  }
+
   /* ---------- Save (dirty rows only — stop at the first failure,
      K4; the §7.4 never-stale lifecycle) ---------- */
   async function saveSettings() {
@@ -499,6 +553,9 @@ export async function mount(root) {
       );
       const input = root.querySelector("#set-" + failure.key);
       if (input) input.focus();
+      /* A brand row that DID land before the failure changed the app
+         (K4 saves the prefix) — the open document re-reads it too. */
+      await reapplyBrand(saved);
     } else {
       /* One status line (role=status) — a saved restart-required
          row says so (the owner is never told "saved" and then sees
@@ -511,6 +568,10 @@ export async function mount(root) {
           (anyRestart ? " — applies on the next restart" : ""),
       );
       await loadSettings(); // every badge/value is the settled state
+      /* …and the brand strings apply to the OPEN document (no reload) —
+         additive to the catalogue re-GET above, still inside the
+         saveInFlight guard (phase 190, task 03). */
+      await reapplyBrand(saved);
     }
     saveInFlight = false;
     if (saveBtn) {
@@ -535,6 +596,7 @@ export async function mount(root) {
     }
     announce(`${envVar} is back to the environment value.`);
     await loadSettings(); // the badge falls back to env/default
+    await reapplyBrand([key]); // …and the open document falls back too
   }
 
   /* ---------- Clear all overrides (the house two-step inline
@@ -570,6 +632,7 @@ export async function mount(root) {
     restore();
     announce(`Cleared ${cleared} overrides.`);
     await loadSettings(); // every badge falls back to env/default
+    await reapplyBrand(BRAND_KEYS); // every brand string may have moved
   }
 
   function showClearAllConfirm() {