Rewrite player + fix matching metadata loss

Streaming: Custom range-aware HTTP endpoint. Returns 206 Partial Content
for Range requests (with Content-Range, Content-Length, Accept-Ranges).
This was the root cause of broken seeking — Starlette's default
FileResponse behavior wasn't reliable across all clients. Now seeking
works natively via standard HTML5 audio.

Player: Full rewrite. Cleaner separation between absolute book time and
per-track time. Track switching uses pendingSeek + canplay/loadedmetadata
handlers. Console logs for debugging. Removed crossOrigin to avoid CORS
issues. Removed hls.js entirely.

Matcher: Critical bug fix — get_work_details (OpenLibrary) was returning
a sparse MatchResult that REPLACED the rich search result, losing cover,
author, year. New _enrich_match merges details into best without
overwriting existing values (except description/chapters which are
preferred from details fetch).

Scoring: Lenient min/max-weighted similarity (better for German episodic
titles like "Die drei ??? - Folge 215"). Thresholds lowered:
UNCERTAIN 0.50→0.40, AUTO_ACCEPT 0.75→0.65.

Search: search_for_item now returns ALL fields (narrator, publisher,
series, genres, description, language) so manual apply has full data.

Apply: apply_match now always constructs from body first, then enriches
with details. Previously OL applies would lose cover/author. Added
detailed logging across matcher and apply paths.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/routers/matching.py

@@ -1,17 +1,19 @@
 import asyncio
+import logging
 from fastapi import APIRouter, Depends, HTTPException, BackgroundTasks
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from ..dependencies import get_db, get_current_user, require_admin
 from ..models.user import User
 from ..models.media_item import LibraryItem
-from ..services.matcher import match_audiobook, search_for_item, _apply_match, _score_result
+from ..services.matcher import match_audiobook, search_for_item, _apply_match, _enrich_match
 from ..services.matching.musicbrainz import get_release_details
 from ..services.matching.open_library import get_work_details
-from ..services.matching.google_books import search_google_books
 from ..services.matching.base import MatchResult
 from datetime import datetime
 
+logger = logging.getLogger(__name__)
+
 router = APIRouter(prefix="/api/items", tags=["matching"])
 
 
@@ -59,7 +61,7 @@ async def apply_match(
 ):
     """
     Wendet einen manuell gewählten Match-Treffer an.
-    body: { source, id, title, author, ... }
+    body: { source, id, title, author, narrator, description, publisher, publishYear, series, seriesSequence, language, genres, cover, ... }
     """
     result = await db.execute(select(LibraryItem).where(LibraryItem.id == item_id))
     item = result.scalar_one_or_none()
@@ -69,27 +71,44 @@ async def apply_match(
     source = body.get("source", "manual")
     source_id = body.get("id", "")
 
-    # Versuche Details zu laden wenn MusicBrainz/OpenLibrary
-    match_result = None
-    if source == "musicbrainz":
-        match_result = await get_release_details(source_id)
-    elif source == "open_library":
-        from ..services.matching.open_library import get_work_details
-        match_result = await get_work_details(source_id)
+    logger.info(
+        f"Manual apply: item={item_id} source={source} source_id={source_id} "
+        f"body_keys={sorted(body.keys())}"
+    )
 
-    if not match_result:
-        # Fallback: nur die übergebenen Daten verwenden
-        match_result = MatchResult(
-            source=source,
-            source_id=source_id,
-            title=body.get("title", item.title or ""),
-            author=body.get("author"),
-            publish_year=body.get("publishYear"),
-            cover_url=body.get("cover"),
-            confidence=1.0,
-        )
+    # Immer aus body konstruieren (search_for_item liefert jetzt alle Felder)
+    match_result = MatchResult(
+        source=source,
+        source_id=source_id,
+        title=body.get("title") or item.title or "",
+        subtitle=body.get("subtitle"),
+        author=body.get("author"),
+        narrator=body.get("narrator"),
+        description=body.get("description"),
+        publisher=body.get("publisher"),
+        publish_year=body.get("publishYear"),
+        series=body.get("series"),
+        series_sequence=body.get("seriesSequence"),
+        language=body.get("language"),
+        genres=body.get("genres") or [],
+        cover_url=body.get("cover"),
+        confidence=1.0,
+    )
 
-    match_result.confidence = 1.0  # Manuell → immer akzeptieren
+    # Mit Details anreichern (Beschreibung, Kapitel) — überschreibt keine vorhandenen Werte
+    try:
+        if source == "musicbrainz":
+            details = await get_release_details(source_id)
+            if details:
+                _enrich_match(match_result, details)
+        elif source == "open_library":
+            details = await get_work_details(source_id)
+            if details:
+                _enrich_match(match_result, details)
+    except Exception as e:
+        logger.warning(f"Details-Laden fehlgeschlagen ({source}: {source_id}): {e}")
+
+    match_result.confidence = 1.0
     await _apply_match(db, item, match_result, confidence=1.0)
     item.match_locked = True
     item.updated_at = datetime.utcnow()