v2.0.1 — collab-attachments size cap + oumta overview tiles

- relay: raise /api/collab-attachments + /api/attachments/upload POST
  size limit from 256KB to 15MB, matching /api/attachments. Previous
  limit silently dropped any collab image >~100KB as 413 (envelope
  overhead pushes even modest JPEGs past the cap), leaving puller
  clients with broken <img src="uploads/..."> references.
- oumta-dashboard: centre overview tiles, bump value font to 56px,
  introduce .oumta-fail alarm state that paints the full tile red with
  white text. Toggled from JS for cluster state=down, workloads down
  >0, and open incidents >0. Fail colour uses --t-danger so it stays
  in sync with the "unavailable" workload labels.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

public/plugins/oumta-dashboard/oumta-dashboard.css

@@ -46,6 +46,9 @@
     border-radius: var(--ui-radius-card);
     padding: 14px 16px;
     display: flex; flex-direction: column; gap: 4px;
+    align-items: center;
+    text-align: center;
+    transition: background-color 0.2s, border-color 0.2s, color 0.2s;
 }
 .oumta-card-wide { grid-column: span 4; }
 .oumta-card-label {
@@ -57,18 +60,36 @@
 }
 .oumta-card-value {
     font-family: var(--font-content, monospace);
-    font-size: 28px;
+    font-size: 56px;
     color: var(--t-bright);
     font-weight: bold;
+    line-height: 1.05;
 }
-.oumta-card-value-sm { font-size: 14px; font-weight: normal; }
+.oumta-card-value-sm { font-size: 18px; font-weight: normal; line-height: 1.3; }
 .oumta-card-sub { font-size: 10px; color: var(--t-dim); }
 .oumta-danger { color: var(--t-danger); }
 
+/* Fail state: whole card goes red; label, value, sub all flip to white
+ * so the box reads as a single alarm tile rather than a coloured number
+ * on dark chrome. Triggered from JS via the oumta-fail class. Uses the
+ * theme's --t-danger to stay consistent with the "unavailable" state
+ * labels and workload state colours elsewhere in the dashboard. */
+.oumta-card.oumta-fail {
+    background: var(--t-danger);
+    border-color: var(--t-danger);
+    color: #fff;
+}
+.oumta-card.oumta-fail .oumta-card-label,
+.oumta-card.oumta-fail .oumta-card-value,
+.oumta-card.oumta-fail .oumta-card-sub {
+    color: #fff;
+}
+
 .oumta-cluster-status[data-state="healthy"]   .oumta-card-value { color: #4ade80; }
 .oumta-cluster-status[data-state="degraded"]  .oumta-card-value { color: #fb923c; }
-.oumta-cluster-status[data-state="down"]      .oumta-card-value { color: var(--t-danger); }
 .oumta-cluster-status[data-state="unknown"]   .oumta-card-value { color: var(--t-dim); }
+/* data-state="down" is handled by .oumta-fail (toggled from JS) so the
+ * cluster tile goes fully red + white like the other alarms. */
 
 /* ── Attention list ── */
 .oumta-section { margin-top: 8px; }