feat(e2e): use direct HTTP for chapter scraping, cap TTS at 200 chars

- e2e fixture: replace single contentClient with directClient (plain HTTP)
  for chapter/metadata/ranking + contentClient (Browserless) for urlClient
  only — matches production wiring and is significantly faster
- server: add max_chars field to audio request body; truncates stripped text
  to N runes before sending to Kokoro (used by e2e for quick TTS tests)
- fix: move RankingItem to scraper package to break novelfire→storage import
  cycle; storage.RankingItem is now a type alias for backward compat
- fix: update stale New() call in novelfire integration test (missing args)
- fix: replace removed blob-ranking methods in storage integration test with
  current per-item API (UpsertRankingItem/ListRankingItems/RankingLastUpdated)
- justfile: add test-e2e and e2e tasks

scraper/internal/scraper/interfaces.go

@@ -3,7 +3,10 @@
 // wires them together without knowing anything about the concrete provider.
 package scraper
 
-import "context"
+import (
+	"context"
+	"time"
+)
 
 // ─── Domain types ────────────────────────────────────────────────────────────
 
@@ -58,6 +61,19 @@ type Chapter struct {
 	Text string
 }
 
+// RankingItem represents a single entry in the novel ranking list.
+type RankingItem struct {
+	Rank      int       `json:"rank"`
+	Slug      string    `json:"slug"`
+	Title     string    `json:"title"`
+	Author    string    `json:"author,omitempty"`
+	Cover     string    `json:"cover,omitempty"`
+	Status    string    `json:"status,omitempty"`
+	Genres    []string  `json:"genres,omitempty"`
+	SourceURL string    `json:"source_url,omitempty"`
+	Updated   time.Time `json:"updated,omitempty"`
+}
+
 // ─── Scraping selector descriptors ───────────────────────────────────────────
 
 // Selector describes how to locate an element in an HTML document.