dashboard + dispatcher — UX props, trim head+tail, cols, link direct

dashboard:
- job_id, AUV GP1/GP2 (serial en tooltip), segment_label, duree reelle,
  nb frames, nb hors-eau trimes
- lien viser plain <a href> (plus de POST ni popup). Affiche uniquement
  si job.done ET viser_url persistee (demo.py kept alive)
- CSS minimal: flex row, separateurs, skipped en italic mute

dispatcher:
- trim head ET tail (AUV hors-eau en debut + fin de session)
- migration DB: trimmed_head, trimmed_tail, video_duration_s
- do_extract persiste total_duration_s + trimmed counts via set_status
- run_one: RuntimeError(skipped_short) preserve le status=skipped
- min_frames underwater pour skip les segments trop courts
- ram_budget 0.45 -> 0.35 (OOM rc=137 avec 8237 frames sur 62GB RAM)

app/templates/_jobs_table.html

@@ -18,13 +18,15 @@
             {% else %}<span class="sq">■</span>{% endif %}
           </span>
           <span class="label">
-            {{ j.auv }}/{{ j.gopro_serial }}/{{ j.segment_label }}
+            <span class="job-id">#{{ j.id }}</span>
+            <span class="auv-gp" title="{{ j.gopro_serial }}">{{ j.auv }} {{ j.gp_label }}</span>
+            <span class="seg">{{ j.segment_label }}</span>
+            {% if j.video_duration_fmt != '—' %}<span class="meta">{{ j.video_duration_fmt }}{% if j.frame_count %} · {{ j.frame_count }} f{% if j.trimmed_total %} · −{{ j.trimmed_total }} hors-eau{% endif %}{% endif %}</span>{% endif %}
             {% if j.status in ('extracting','running') %}
               <span class="prog-wrap"><span class="prog-fill" style="width:{{ j.progress }}%"></span><span class="prog-text">{{ j.progress }}%</span></span>
             {% endif %}
-            {% if j.status == 'done' and j.ply_path %}
-              <button class="ext viewer-btn" data-view-url="jobs/{{ j.id }}/live" title="viser natif de demo.py (camera frustums, filtre confiance) — si encore alive">live</button>
-              <button class="ext viewer-btn" data-view-url="jobs/{{ j.id }}/view" title="viser_ply.py standalone — toujours dispo">PLY</button>
+            {% if j.status == 'done' and j.viser_url %}
+              <a class="ext viser-link" href="{{ j.viser_url }}" target="_blank" rel="noopener" title="viser natif ({{ j.viser_url }})">viser</a>
             {% endif %}
           </span>
           <span class="dur">{{ j._duration }}</span>