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

AGENTS.md

@@ -0,0 +1,89 @@
+# libnovel Project
+
+Go web scraper for novelfire.net with TTS support via Kokoro-FastAPI.
+
+## Architecture
+
+```
+scraper/
+├── cmd/scraper/main.go           # Entry point: 'run' (one-shot) and 'serve' (HTTP server)
+├── internal/
+│   ├── orchestrator/orchestrator.go  # Coordinates catalogue walk, metadata extraction, chapter scraping
+│   ├── browser/                       # Browser client (content/scrape/cdp strategies) via Browserless
+│   ├── novelfire/scraper.go          # novelfire.net specific scraping logic
+│   ├── server/server.go              # HTTP API (POST /scrape, POST /scrape/book)
+│   ├── writer/writer.go              # File writer (metadata.yaml, chapter .md files)
+│   └── scraper/interfaces.go         # NovelScraper interface definition
+└── static/books/                     # Output directory for scraped content
+```
+
+## Key Concepts
+
+- **Orchestrator**: Manages concurrency - catalogue streaming → per-book metadata goroutines → chapter worker pool
+- **Browser Client**: 3 strategies (content/scrape/cdp) via Browserless Chrome container
+- **Writer**: Writes metadata.yaml and chapter markdown files to `static/books/{slug}/vol-0/1-50/`
+- **Server**: HTTP API with async scrape jobs, UI for browsing books/chapters, chapter-text endpoint for TTS
+
+## Commands
+
+```bash
+# Build
+cd scraper && go build -o bin/scraper ./cmd/scraper
+
+# One-shot scrape (full catalogue)
+./bin/scraper run
+
+# Single book
+./bin/scraper run --url https://novelfire.net/book/xxx
+
+# HTTP server
+./bin/scraper serve
+
+# Tests
+cd scraper && go test ./...
+```
+
+## Environment Variables
+
+| Variable | Description | Default |
+|----------|-------------|---------|
+| BROWSERLESS_URL | Browserless Chrome endpoint | http://localhost:3000 |
+| BROWSERLESS_STRATEGY | content \| scrape \| cdp | content |
+| SCRAPER_WORKERS | Chapter goroutines | NumCPU |
+| SCRAPER_STATIC_ROOT | Output directory | ./static/books |
+| SCRAPER_HTTP_ADDR | HTTP listen address | :8080 |
+| KOKORO_URL | Kokoro TTS endpoint | http://localhost:8880 |
+| KOKORO_VOICE | Default TTS voice | af_bella |
+| LOG_LEVEL | debug \| info \| warn \| error | info |
+
+## Docker
+
+```bash
+docker-compose up -d  # Starts browserless, kokoro, scraper
+```
+
+## Code Patterns
+
+- Uses `log/slog` for structured logging
+- Context-based cancellation throughout
+- Worker pool pattern in orchestrator (channel + goroutines)
+- Mutex for single async job (409 on concurrent scrape requests)
+
+## AI Context Tips
+
+- Primary files to modify: `orchestrator.go`, `server.go`, `scraper.go`, `browser/*.go`
+- To add new source: implement `NovelScraper` interface from `internal/scraper/interfaces.go`
+- Skip `static/` directory - generated content, not source
+
+## Speed Up AI Sessions (Optional)
+
+For faster AI context loading, use **Context7** (free, local indexing):
+
+```bash
+# Install and index once
+npx @context7/cli@latest index --path . --ignore .aiignore
+
+# After first run, AI tools will query the index instead of re-scanning files
+```
+
+VSCode extension: https://marketplace.visualstudio.com/items?itemName=context7.context7