Phase 15: language + bias als Spalten, Filter, Edit-Form

Bisher waren die DB-Felder sources.language und sources.bias zwar gepflegt
(254/275 Quellen mit bias, 254 mit language), aber in der Verwaltung nicht
sichtbar. Der Admin konnte nicht filtern oder editieren.

Backend (routers/sources.py)
- GlobalSourceCreate + GlobalSourceUpdate Pydantic-Modelle: language +
  bias als Optional[str] erweitert (max 100 / 500 Zeichen).
- SOURCE_UPDATE_COLUMNS: language + bias hinzu.
- INSERT in create_global_source: schreibt language + bias mit.
- Neuer Endpoint GET /api/sources/global/languages: distinct language-Werte
  fuer Frontend-Filter-Dropdown.

Frontend HTML (dashboard.html)
- Grundquellen-Filter-Bar: Sprachen-Dropdown ergaenzt.
- Grundquellen-Tabellenkopf: 2 neue Spalten Sprache (sortable) + Bias.
- modalSource: 2 neue Felder language (mit datalist Vorschlaegen) + bias.
- Kundenquellen-Filter-Bar: Sprachen-Dropdown.
- Kundenquellen-Tabellenkopf: Sprache (sortable) + Bias.

Frontend JS (sources.js)
- loadGlobalSources lädt /languages parallel zu /global + /global/stats,
  populiert beide Sprache-Dropdowns + datalist im Edit-Modal.
- renderGlobalSources: cols 11 -> 13, language+bias-Zellen
  (Bias mit Tooltip fuer Lang-Texte).
- filterGlobalSources: Sprache-Filter, Bias in Suche.
- editGlobalSource: language + bias laden.
- Form-Submit: language + bias mitgesendet.
- renderTenantSources: cols 8 -> 10, language+bias-Zellen.
- tenantFilters um language erweitert, applyTenantFilterAndSort prueft.

Cache-Buster ?v=20260509 (heute) bleibt - Tag wechselt erst morgen.

src/routers/sources.py

@@ -24,7 +24,7 @@ logger = logging.getLogger("verwaltung.sources")
 
 router = APIRouter(prefix="/api/sources", tags=["sources"])
 
-SOURCE_UPDATE_COLUMNS = {"name", "url", "domain", "source_type", "category", "status", "notes"}
+SOURCE_UPDATE_COLUMNS = {"name", "url", "domain", "source_type", "category", "status", "notes", "language", "bias"}
 
 
 @router.get("/meta")
@@ -46,6 +46,8 @@ class GlobalSourceCreate(BaseModel):
     category: str = Field(default="sonstige")
     status: str = Field(default="active", pattern="^(active|inactive)$")
     notes: Optional[str] = None
+    language: Optional[str] = Field(default=None, max_length=100)
+    bias: Optional[str] = Field(default=None, max_length=500)
 
 
 class GlobalSourceUpdate(BaseModel):
@@ -56,6 +58,8 @@ class GlobalSourceUpdate(BaseModel):
     category: Optional[str] = None
     status: Optional[str] = Field(default=None, pattern="^(active|inactive)$")
     notes: Optional[str] = None
+    language: Optional[str] = Field(default=None, max_length=100)
+    bias: Optional[str] = Field(default=None, max_length=500)
 
 
 @router.get("/global")
@@ -139,9 +143,10 @@ async def create_global_source(
             )
 
     cursor = await db.execute(
-        """INSERT INTO sources (name, url, domain, source_type, category, status, notes, added_by, tenant_id)
-           VALUES (?, ?, ?, ?, ?, ?, ?, 'system', NULL)""",
-        (data.name, data.url, data.domain, data.source_type, data.category, data.status, data.notes),
+        """INSERT INTO sources (name, url, domain, source_type, category, status, notes, language, bias, added_by, tenant_id)
+           VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 'system', NULL)""",
+        (data.name, data.url, data.domain, data.source_type, data.category, data.status, data.notes,
+         data.language, data.bias),
     )
     src_id = cursor.lastrowid
     await db.commit()
@@ -223,6 +228,24 @@ async def delete_global_source(
 
 
 
+
+
+
+@router.get("/global/languages")
+async def get_global_languages(
+    admin: dict = Depends(get_current_admin),
+    db: aiosqlite.Connection = Depends(db_dependency),
+):
+    """Distinct language-Werte aus Grundquellen - für Frontend-Filter-Dropdown."""
+    cur = await db.execute("""
+        SELECT DISTINCT language
+        FROM sources
+        WHERE tenant_id IS NULL AND language IS NOT NULL AND language != ''
+        ORDER BY language
+    """)
+    return [r["language"] for r in await cur.fetchall()]
+
+
 @router.get("/global/stats")
 async def get_global_stats(
     admin: dict = Depends(get_current_admin),