Restructure Settings nav, modernize import page, dedup/genres UX polish

Settings is now one top-nav entry with Credentials and Jobs as sidebar
sub-pages (jobs moved from /jobs to /settings/jobs). Manual import page
replaces the bare file input and free-text filename field with a drag-drop
dropzone and a proper file-picker table. Genres page drops the "force"
checkbox for two explicit buttons (Preview / Fix genres now). Dedup's
"Scan now" runs both the file-naming and acoustic passes together, and the
table labels which pass caught each candidate instead of showing the raw
pass name. .btn-ghost gets a visible border so it reads as a real button
next to Delete/Danger actions instead of looking unaligned. Job names
throughout the UI are now human-readable instead of raw job_key strings.

Also includes the fpcalc exit-code fix from earlier (fingerprint index
was discarding valid fingerprints on files with a benign decode warning).

app/routers/dashboard.py

@@ -7,7 +7,7 @@ from sqlalchemy import select
 from app.db import get_db
 from app.models import JobRun
 from app.security.deps import require_auth
-from app.services import beets_service, credential_service, playlist_service
+from app.services import beets_service, credential_service, playlist_service, scheduler_service
 
 router = APIRouter(tags=["dashboard"])
 templates = Jinja2Templates(directory="app/templates")
@@ -44,5 +44,6 @@ async def dashboard(request: Request, user: dict = Depends(require_auth), db=Dep
             "recent_runs": recent_runs,
             "recent_tracks": recent_tracks,
             "auth_states": credential_service.auth_states(db),
+            "humanize_job_key": scheduler_service.humanize_job_key,
         },
     )