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).

pipeline/lib/build-fingerprint-index.py

@@ -65,7 +65,14 @@ def enumerate_library() -> list[tuple[int, str]]:
 
 
 def fpcalc(host_path: str) -> tuple[int, str] | None:
-    """Run fpcalc -raw on a file. Returns (duration_seconds, fingerprint_csv)."""
+    """Run fpcalc -raw on a file. Returns (duration_seconds, fingerprint_csv).
+
+    fpcalc's exit code is not a reliable success signal: it exits non-zero
+    (commonly 3) on a benign trailing-frame decode warning -- seen a lot on
+    game-soundtrack rips with a slightly non-conformant tail -- while still
+    printing a perfectly usable FINGERPRINT line. Whether a fingerprint was
+    actually produced is the real signal, checked below; the exit code is
+    ignored entirely."""
     try:
         proc = subprocess.run(
             ["fpcalc", "-raw", host_path],
@@ -75,8 +82,6 @@ def fpcalc(host_path: str) -> tuple[int, str] | None:
         )
     except (subprocess.TimeoutExpired, FileNotFoundError):
         return None
-    if proc.returncode != 0:
-        return None
     duration = 0
     fingerprint = ""
     for line in proc.stdout.splitlines():