feat: add Kokoro TTS, ranking page, direct HTTP strategy, and chapter-number fix

- Add Kokoro-FastAPI TTS integration to the chapter reader UI:
  - Browser-side MSE streaming with paragraph-level click-to-start
  - Voice selector, speed slider, auto-next with prefetch of the next chapter
  - New GET /ui/chapter-text endpoint that strips Markdown and serves plain text

- Add ranking page (novelfire /ranking scraper, WriteRanking/ReadRankingItems
  in writer, GET /ranking + POST /ranking/refresh + GET /ranking/view routes)
  with local-library annotation and one-click scrape buttons

- Add StrategyDirect (plain HTTP client) as a new browser strategy; the
  default strategy is now 'direct' for chapter fetching and 'content'
  for chapter-list URL retrieval (split via BROWSERLESS_URL_STRATEGY)

- Fix chapter numbering bug: numbers are now derived from the URL path
  (/chapter-N) rather than list position, correcting newest-first ordering

- Add 'refresh <slug>' CLI sub-command to re-scrape a book from its saved
  source_url without knowing the original URL

- Extend NovelScraper interface with RankingProvider (ScrapeRanking)

- Tune scraper timeouts: wait-for-selector reduced to 5 s, GotoOptions
  timeout set to 60 s, content/scrape client defaults raised to 90 s

- Add cover extraction fix (figure.cover > img rather than bare img.cover)

- Add AGENTS.md and .aiignore for AI tooling context

- Add integration tests for browser client and novelfire scraper (build
  tag: integration) and unit tests for chapterNumberFromURL and pagination

.aiignore

@@ -0,0 +1,20 @@
+# AI Indexing Ignore
+# These directories/files are excluded from AI context indexing for speed
+
+# Generated/scraped content
+scraper/static/
+
+# Build artifacts
+scraper/bin/
+*.exe
+
+# Dependencies (if using Go modules, the AI doesn't need vendor/)
+# vendor/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+
+# OS
+.DS_Store