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`.

app/schemas.py

@@ -2077,20 +2077,24 @@ class TokenAuthRequest(BaseModel):
 
 
 class UiSettingsIn(BaseModel):
-    """``PUT /api/ui-settings`` body (phase 91, task 01): a FULL
-    replacement of the single ``ui_settings`` row.
+    """``PUT /api/ui-settings`` body (phase 91, task 01; colors-only since
+    phase 190, task 02): a FULL replacement of the single ``ui_settings``
+    row's 17 COLORS.
 
-    Every field is ``str | None`` — present = a new value (strings are
-    trimmed; empty after the trim is the CLEAR operation, stored as
-    NULL; colors must be ``#rrggbb`` and are lowercased on store),
-    ``null``/absent = "back to the default" (stored as NULL — the Reset
-    button's all-null PUT is exactly the "defaults" operation). The
-    API layer runs the trim/length/hex validation so the 422 details
-    name the offending field (the house fixed-detail style); the
-    built-in→NULL normalization (a color equal to its built-in is
-    stored as NULL — "save the defaults" must leave the row empty, the
-    no-op injection contract) happens there too, next to the palette
-    it normalizes against.
+    Every field is ``str | None`` — present = a new value, ``null``/
+    absent = "back to the default" (stored as NULL — the Reset button's
+    all-null PUT is exactly the "defaults" operation). The API layer
+    runs the hex validation so the 422 details name the offending field
+    (the house fixed-detail style); the built-in→NULL normalization (a
+    color equal to its built-in is stored as NULL — "save the defaults"
+    must leave the row empty, the no-op injection contract) happens
+    there too, next to the palette it normalizes against.
+
+    The three string fields stay on the model for OLD-CLIENT COMPAT and
+    are ACCEPTED AND IGNORED (phase 190 A1): the Settings panel owns the
+    brand strings, so the handler drops them before validating or
+    persisting and the stored columns keep what they hold. Resetting a
+    string is ``DELETE /api/admin/settings/{key}``.
     """
 
     app_name: str | None = None
@@ -2127,7 +2131,9 @@ class UiSettingsOut(BaseModel):
     DB-over-env / DB-over-built-in merge (B1), so the tab always shows
     the LIVE theme — a fresh (row-missing) deployment reports the env
     strings and the built-in palette (the semantic colors report their
-    built-ins — the effective values, the NULL = built-in rule).
+    built-ins — the effective values, the NULL = built-in rule). Since
+    phase 190 (A1) the 3 strings are READ-ONLY here and report the
+    EFFECTIVE value through the panel-row → tab-row → env order.
     """
 
     app_name: str