feat(reader): Word Wise inline vocabulary hints (#4589)

* feat(reader): Word Wise — inline native-language vocabulary hints

Kindle-style Word Wise: a short native-language gloss renders above difficult words
as you read (always-on ruby), gated by a CEFR vocabulary-level slider (A1–C2);
tapping a glossed word opens the existing dictionary.

- Pipeline: CEFR→frequency-rank difficulty, inflection-aware gloss index, pure
  offset-aware planner (EN regex + jieba for CJK).
- Rendering: <ruby cfi-skip>…<rt cfi-inert> injected per occurrence — CFI-transparent
  (verified), so highlights/bookmarks/progress are unaffected; kept out of TTS word
  offsets and find-in-book.
- Delivery: gloss packs are version-controlled in data/wordwise/, mirrored to R2, and
  downloaded on demand into local storage (sha-verified, single-flight) when enabled.
- Settings: a Word Wise sub-page under Settings → Language (enable, level, hint
  language, per-pack download/manage, auto-download toggle).
- Build tooling: scripts/build-wordwise-data.mjs (ECDICT / CC-CEDICT+HSK / WikDict +
  FrequencyWords, with lemmatization) and scripts/sync-wordwise-r2.mjs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* data(wordwise): bundled gloss packs + manifest + attribution

13 frequency-trimmed gloss packs (en↔中文 + es/fr/de/pt/it/ru↔en, ~19 MB) generated
by build-wordwise-data.mjs from ECDICT (MIT), CC-CEDICT + HSK, and WikDict +
FrequencyWords (CC-BY-SA). Source of truth, mirrored to the CDN via `pnpm wordwise:sync`.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/readest-app/src/app/reader/utils/iframeEventHandlers.ts

@@ -1,5 +1,6 @@
 import { DOUBLE_CLICK_INTERVAL_THRESHOLD_MS, LONG_HOLD_THRESHOLD } from '@/services/constants';
 import { eventDispatcher } from '@/utils/event';
+import { findGlossWord } from '@/app/reader/utils/wordwiseRuby';
 
 let lastClickTime = 0;
 let longHoldTimeout: ReturnType<typeof setTimeout> | null = null;
@@ -224,6 +225,15 @@ export const handleClick = (
       return;
     }
 
+    // Word Wise: tapping a glossed word looks it up in the dictionary. Checked
+    // after the drag/long-hold guards so only a clean single tap triggers it.
+    const glossWord = findGlossWord(element);
+    if (glossWord) {
+      const ruby = element?.closest('ruby.ww-gloss') ?? null;
+      eventDispatcher.dispatch('wordwise-dictionary', { bookKey, element: ruby, word: glossWord });
+      return;
+    }
+
     window.postMessage(
       {
         type: 'iframe-single-click',