v0.8.1:0 - delete model weights from disk via card trash icon

Each model card now shows whether its weights are present on disk
(with GB size) or not yet downloaded. When present and the model
isn't currently loaded, a trash icon appears; clicking it pops a
confirmation showing exactly how many GB will be freed and on
which Spark(s), then runs rm -rf on the HF cache directory via SSH.

Cluster-mode models are removed from both Sparks; solo-mode from
Spark 1 only. Safety rails: refuses to delete the currently-loaded
model, refuses during an in-flight swap or download, and the
catalog entry stays intact so it can be re-downloaded anytime.

Backend:
  - new image/app/disk.py: probe_disk + delete_from_disk over SSH
  - GET  /api/models/disk-status — parallel probe across all catalog models
  - DELETE /api/models/{key}/disk — guarded rm -rf, logs to connectivity events

Frontend:
  - on-disk / not-downloaded pills on every card
  - trash icon-btn in card-actions row (hidden when not on disk)
  - confirmation dialog showing per-host bytes-to-free
  - disk-status re-checked every 60s

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

image/app/static/app.js

@@ -18,6 +18,8 @@ const state = {
   configured: true,
   timer_handle: null,
   deep_health: {},
+  disk_status: {},         // keyed by model key: { on_disk, total_bytes, per_host }
+  disk_status_loaded: false,
 };
 
 const el = (sel) => document.querySelector(sel);
@@ -57,12 +59,36 @@ function renderCards() {
       ? `<div class="desc">${escapeHtml(m.description)}</div>`
       : '';
     const customPill = m.custom ? `<span class="tag custom-pill">custom</span>` : '';
+    // Disk-presence pill + trash button. Until /api/models/disk-status comes back,
+    // we don't know — render a neutral placeholder.
+    const disk = state.disk_status[key];
+    let diskPill = '';
+    if (state.disk_status_loaded) {
+      if (disk && disk.on_disk) {
+        const gb = (disk.total_bytes / 1e9);
+        diskPill = `<span class="tag on-disk" title="Weights present on disk">on disk · ${gb.toFixed(1)} GB</span>`;
+      } else {
+        diskPill = `<span class="tag not-on-disk" title="Weights not downloaded">not downloaded</span>`;
+      }
+    }
+    // Trash button — hidden if not on disk; disabled (with tooltip) if currently loaded.
+    let trashBtn = '';
+    if (state.disk_status_loaded && disk && disk.on_disk) {
+      const disabled = isActive || isSwapping;
+      const tip = isActive
+        ? 'Currently loaded — switch to another model first'
+        : isSwapping
+        ? 'A swap is in progress'
+        : 'Delete weights from disk';
+      trashBtn = `<button class="icon-btn danger" data-disk-del-key="${key}" title="${escapeHtml(tip)}" aria-label="Delete from disk" ${disabled ? 'disabled' : ''}>${trashIcon}</button>`;
+    }
     card.innerHTML = `
       <div class="name">${escapeHtml(m.display_name)}</div>
       <div class="meta">
         <span class="tag mode-${m.mode}">${m.mode}</span>
         <span class="tag">${m.size_gb} GB</span>
         ${customPill}
+        ${diskPill}
         ${(m.capabilities || []).map(c => `<span class="tag cap">${escapeHtml(c)}</span>`).join('')}
       </div>
       ${desc}
@@ -76,6 +102,7 @@ function renderCards() {
         </button>
         <button class="btn test-btn" data-test-key="${key}" title="Pre-flight check the launch command without starting the engine">Test</button>
         <button class="btn adv-btn" data-adv-key="${key}" title="Advanced settings">Advanced</button>
+        ${trashBtn}
       </div>
       <div class="test-result hidden" data-test-result-for="${key}"></div>
     `;
@@ -90,8 +117,13 @@ function renderCards() {
   for (const btn of root.querySelectorAll('[data-test-key]')) {
     btn.addEventListener('click', () => testLaunch(btn.dataset.testKey, btn));
   }
+  for (const btn of root.querySelectorAll('[data-disk-del-key]')) {
+    btn.addEventListener('click', () => openDiskDeleteDialog(btn.dataset.diskDelKey));
+  }
 }
 
+const trashIcon = '<svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><polyline points="3 6 5 6 21 6"></polyline><path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6"></path><path d="M10 11v6"></path><path d="M14 11v6"></path><path d="M9 6V4a2 2 0 0 1 2-2h2a2 2 0 0 1 2 2v2"></path></svg>';
+
 async function testLaunch(key, btn) {
   const resultEl = document.querySelector(`[data-test-result-for="${key}"]`);
   if (!resultEl) return;
@@ -739,6 +771,78 @@ async function loadModels() {
   state.models = data.models || {};
 }
 
+async function loadDiskStatus() {
+  // Probes each catalog model's HF cache over SSH; takes a beat. Best-effort.
+  try {
+    const r = await fetchJSON('/api/models/disk-status');
+    if (r && r.models) {
+      state.disk_status = r.models;
+      state.disk_status_loaded = true;
+      renderCards();
+    }
+  } catch (e) {
+    // Silent — pills just won't render. Don't block dashboard.
+    console.warn('disk-status probe failed:', e.message);
+  }
+}
+
+function fmtBytesShort(n) {
+  if (!Number.isFinite(n) || n <= 0) return '0 B';
+  if (n >= 1e9) return `${(n / 1e9).toFixed(1)} GB`;
+  if (n >= 1e6) return `${(n / 1e6).toFixed(1)} MB`;
+  if (n >= 1e3) return `${(n / 1e3).toFixed(1)} KB`;
+  return `${n} B`;
+}
+
+function openDiskDeleteDialog(key) {
+  const m = state.models[key];
+  const disk = state.disk_status[key];
+  if (!m || !disk || !disk.on_disk) return;
+  const dlg = el('#disk-delete-dialog');
+  el('#dd-summary').innerHTML = `Free <strong>${fmtBytesShort(disk.total_bytes)}</strong> by removing <strong>${escapeHtml(m.display_name)}</strong> (<code>${escapeHtml(m.repo)}</code>) from disk.`;
+  const hostsEl = el('#dd-hosts');
+  hostsEl.innerHTML = '';
+  for (const h of (disk.per_host || [])) {
+    if (!h.on_disk) continue;
+    const li = document.createElement('li');
+    li.innerHTML = `<code>${escapeHtml(h.host)}</code> — ${fmtBytesShort(h.size_bytes)}`;
+    hostsEl.appendChild(li);
+  }
+  const errEl = el('#dd-error');
+  errEl.classList.add('hidden');
+  errEl.textContent = '';
+
+  const confirm = el('#dd-confirm');
+  const cancel = el('#dd-cancel');
+  const onCancel = () => dlg.close();
+  const onConfirm = async () => {
+    confirm.disabled = true;
+    cancel.disabled = true;
+    confirm.textContent = 'Deleting…';
+    try {
+      const r = await fetchJSON(`/api/models/${encodeURIComponent(key)}/disk`, { method: 'DELETE' });
+      dlg.close();
+      // Optimistically clear local disk state for this key, then refresh.
+      delete state.disk_status[key];
+      renderCards();
+      // Eagerly re-probe so size is accurate (and shows "not downloaded" pill).
+      loadDiskStatus();
+      const freed = r && typeof r.bytes_freed === 'number' ? fmtBytesShort(r.bytes_freed) : '';
+      console.log(`Deleted ${m.display_name} from disk${freed ? ` — freed ${freed}` : ''}.`);
+    } catch (e) {
+      errEl.textContent = e.message || 'Delete failed';
+      errEl.classList.remove('hidden');
+    } finally {
+      confirm.disabled = false;
+      cancel.disabled = false;
+      confirm.textContent = 'Delete from disk';
+    }
+  };
+  cancel.onclick = onCancel;
+  confirm.onclick = onConfirm;
+  dlg.showModal();
+}
+
 async function triggerSwap(modelKey) {
   if (state.swap_job_id) return;
   try {
@@ -1523,9 +1627,12 @@ async function init() {
   await renderServices();
   pollHardware();
   pollUpdates();
+  // Disk-status probe runs after first paint — slow over SSH and not blocking.
+  loadDiskStatus();
   setInterval(pollStatus, 5000);
   setInterval(pollHardware, 8000);    // every 8s
   setInterval(pollUpdates, 300000);  // every 5 min
+  setInterval(loadDiskStatus, 60000); // every 60s — disk state changes rarely
 }
 
 init();