fix: web/ quick wins — CSS cleanup, ARIA tabs, and file header comments

CSS:
- Remove duplicate li::before block in app-search.css
- Fix typo: search-reuslt → search-result in app-search.css
- Remove commented-out CSS rules in app-flash.css
- Add descriptive header comment to all 27 CSS component files

JS:
- Complete WAI-ARIA Tabs pattern: generate IDs, add aria-controls on
  tab buttons and aria-labelledby on tab panels (app-tabs.js)
- Add JSDoc header comments to ~33 JS files (core + components)
- Add explanatory block comment to app-boot.js (why classic IIFE)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/js/core/app-confirm-dialog.js

@@ -1,3 +1,6 @@
+/**
+ * Promise-based confirm dialog controller with variant inference, focus trap, and native fallback.
+ */
 import { warnOnce } from './app-dom.js';
 
 const VARIANTS = new Set(['default', 'warning', 'danger']);

web/js/core/app-detail-page-factory.js

@@ -1,3 +1,6 @@
+/**
+ * Factory for standard detail pages — form dirty-tracking, unsaved indicator, validation routing, and keyboard save.
+ */
 import { initDetailActionPolicy } from './app-details-action-policy.js';
 import { confirmDialog } from './app-confirm-dialog.js';
 

web/js/core/app-details-action-policy.js

@@ -1,3 +1,6 @@
+/**
+ * Form submit policy for detail pages — confirm dialogs, double-submit prevention, and aria-busy.
+ */
 import { confirmDialog, requestSubmitWithFallback } from './app-confirm-dialog.js';
 
 const escapeAttr = (value) => {

web/js/core/app-details-open-state.js

@@ -1,3 +1,6 @@
+/**
+ * Persists open/closed state of details elements to localStorage by key.
+ */
 const toElement = (value) => {
   if (value instanceof HTMLElement) {
     return value;

web/js/core/app-dom.js

@@ -1,3 +1,6 @@
+/**
+ * DOM utility helpers — safe element lookup with missing-element warnings and telemetry.
+ */
 import { telemetry } from './app-telemetry.js';
 
 const warned = new Set();

web/js/core/app-page-config.js

@@ -1,3 +1,6 @@
+/**
+ * Reads JSON configuration embedded in the page via script#page-config-{id} elements.
+ */
 import { warnOnce } from './app-dom.js';
 
 export function readPageConfig(configId, root = document) {

web/js/core/app-telemetry.js

@@ -1,3 +1,6 @@
+/**
+ * Frontend event telemetry — captures UI events with deduplication, sampling, and rate limiting.
+ */
 const DEFAULT_SAMPLE_RATE = 0.2;
 const DEFAULT_DEDUPE_TTL_MS = 5 * 60 * 1000;
 const DEFAULT_MAX_EVENTS_PER_MINUTE = 20;