Location: say why it failed, retry once, show permission status

The ⌖ button reported 'Location access denied' for every failure, including timeouts and
no-GPS-fix errors that have nothing to do with permission.

- Specific messages for denied / no fix / timeout, with the exact iPhone steps (Safari tab vs
  installed web app) and the error code for diagnosis
- One patient high-accuracy retry for slow or cold GPS fixes (a real denial is not retried)
- Live permission status line under the search row (allowed / not asked / blocked)
- Mentions Safari content blockers as a possible cause

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/public/app-ui.css

@@ -324,3 +324,9 @@ body.map-fs #tab-unified-map { padding: 0; }
 .alert-full p { margin: 0 0 0.6rem; }
 .alert-pre { white-space: pre-wrap; }
 .alert-meta { font-size: 0.74rem; color: var(--ink-light); }
+
+/* Location permission status line */
+.geo-status { font-size: 0.8rem; line-height: 1.45; color: var(--ink-light); margin: 0.5rem 0.15rem 0; padding: 0.5rem 0.75rem; border-radius: 12px; background: var(--paper-darker); }
+.geo-status.hidden { display: none; }
+.geo-status.ok { color: #22c55e; }
+.geo-status.warn { color: var(--ink); background: color-mix(in srgb, #ef4444 14%, var(--paper-darker)); border: 1px solid color-mix(in srgb, #ef4444 45%, transparent); }