fix(settings): maintenance tiles start collapsed; remember manual open state

GpuAgentCard was hardcoded :open=true, HeadsCard opened whenever any head
existed, TagEvalCard whenever a persisted run existed — so a fresh Settings
load greeted the operator with several tiles already expanded. All three now
force-open only while their task is actually running (the #877 resurface
behavior on the busy-driven tiles is untouched).

MaintenanceTile additionally persists MANUAL expand/collapse per tile in
localStorage, so the section reloads the way the operator left it; a forced
open while a task runs stays transient and is never saved as a preference.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CDgx8bQS5YrGRK76v8HUnM

frontend/src/components/settings/GpuAgentCard.vue

@@ -3,7 +3,6 @@
     icon="mdi-expansion-card"
     title="GPU agent (CCIP + crops)"
     blurb="Connect a desktop-GPU agent to embed characters (CCIP) and crops. It pulls work over HTTP — your database and Redis stay private."
-    :open="true"
   >
     <p class="fc-muted text-body-2 mb-3">
       The agent is a container you run on the machine with the GPU. It

frontend/src/components/settings/HeadsCard.vue

@@ -3,7 +3,7 @@
     icon="mdi-brain"
     title="Concept heads (the learning suggester)"
     blurb="Train the per-concept heads that turn your tags into suggestions — they replace Camie and sharpen every time you accept or reject."
-    :open="headCount > 0 || running"
+    :open="running"
   >
     <p class="fc-muted text-body-2 mb-3">
       A <strong>head</strong> is a tiny classifier trained on the SigLIP

frontend/src/components/settings/TagEvalCard.vue

@@ -3,7 +3,7 @@
     icon="mdi-flask-outline"
     title="Tagging eval (heads vs centroid)"
     blurb="Measure whether a trained head beats the old centroid on your own tags — and whether tagging more sharpens it."
-    :open="!!run"
+    :open="running"
   >
     <p class="fc-muted text-body-2 mb-3">
       Reuses the SigLIP embeddings already stored on your images (no re-embed, no