feat(x-scraper): X-Recherche-Konten im Verwaltungsportal verwalten

Neuer Sub-Tab "X-Recherche-Konten" unter Quellen: die X-Login-Konten,
mit denen der Monitor bei X scrapt (twscrape-Account-Pool), anzeigen,
hinzufuegen, Cookies erneuern, aktiv/inaktiv schalten, entfernen, plus
Sperren-Reset.

- neuer Router x_scraper.py, verwaltet den twscrape-Pool ueber dessen API
- X_ACCOUNTS_DB_PATH in config.py
- twscrape als Abhaengigkeit (git-main-Pin)
- Sub-Tab, Tabelle und zwei Modals in dashboard.html, Logik in x-scraper.js

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/main.py

@@ -11,7 +11,7 @@ from fastapi.staticfiles import StaticFiles
 from fastapi.responses import FileResponse
 
 from config import STATIC_DIR, PORT
-from routers import auth, organizations, licenses, users, dashboard, sources, token_usage, audit, translation
+from routers import auth, organizations, licenses, users, dashboard, sources, token_usage, audit, translation, x_scraper
 
 logging.basicConfig(
     level=logging.INFO,
@@ -43,6 +43,7 @@ app.include_router(sources.router)
 app.include_router(token_usage.router)
 app.include_router(audit.router)
 app.include_router(translation.router)
+app.include_router(x_scraper.router)
 
 # --- Statische Dateien ---
 app.mount("/static", StaticFiles(directory=STATIC_DIR), name="static")