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/templates/jobs/_runs_table.html

@@ -1,11 +1,11 @@
 {% set status_badge = {"running": "badge-info badge-pulse", "success": "badge-success", "failed": "badge-danger", "skipped_lock": "badge-muted"} %}
 {% for run in recent_runs %}
 <tr>
-  <td>{{ run.job_key }}</td>
+  <td title="{{ run.job_key }}">{{ humanize_job_key(run.job_key) }}</td>
   <td><span class="badge {{ status_badge.get(run.status, 'badge-muted') }}">{{ run.status }}</span></td>
   <td class="muted">{{ run.triggered_by }}</td>
   <td>{{ run.summary or "" }}</td>
-  <td>{% if run.log_path %}<a href="/jobs/runs/{{ run.id }}/log" target="_blank" class="btn btn-sm btn-ghost">Log</a>{% endif %}</td>
+  <td>{% if run.log_path %}<a href="/settings/jobs/runs/{{ run.id }}/log" target="_blank" class="btn btn-sm btn-ghost">Log</a>{% endif %}</td>
 </tr>
 {% else %}
 <tr class="empty-row"><td colspan="5" class="muted">No job runs yet.</td></tr>