feat(frontend): gate body editor when task body is auto-maintained

When consolidated_at is set on a task, the editor:
- shows a banner above the body indicating the body is auto-summarized
- hides the Write tab; locks the body view to read-only preview
- exposes a Re-consolidate button that calls POST /api/tasks/:id/consolidate
  and refreshes the body from the response

Pre-consolidation behavior is unchanged — the Write tab and TiptapEditor
remain available.

frontend/src/views/TaskEditorView.vue

@@ -109,6 +109,29 @@ async function toggleSubTask(sub: SubTask) {
 }
 const showPreview = ref(false);
 const sidebarOpen = ref(true);
+const reconsolidating = ref(false);
+
+// Body is machine-maintained once a consolidation pass has run. The editor
+// is gated to read-only in that state; the user can re-consolidate or rely
+// on log_work entries flowing into the next auto pass.
+const isBodyAutoMaintained = computed(() => consolidatedAt.value !== null);
+
+async function reconsolidate() {
+  if (!taskId.value || reconsolidating.value) return;
+  reconsolidating.value = true;
+  try {
+    const { consolidateTask } = await import("@/api/client");
+    const updated = await consolidateTask(taskId.value);
+    body.value = updated.body;
+    consolidatedAt.value = updated.consolidated_at ?? null;
+    savedBody = body.value;
+    toast.show("Task summary refreshed");
+  } catch {
+    toast.show("Failed to re-consolidate", "error");
+  } finally {
+    reconsolidating.value = false;
+  }
+}
 const editorRef = ref<InstanceType<typeof TiptapEditor> | null>(null);
 const titleRef = ref<HTMLInputElement | null>(null);
 const tiptapEditor = computed<Editor | null>(() => {
@@ -462,13 +485,33 @@ useEditorGuards(dirty, save);
       <!-- ── Main column ─────────────────────────────────────────── -->
       <div class="task-main" @keydown.ctrl.e.prevent="tiptapEditor?.commands.focus()">
 
-        <!-- Write / Preview tabs + toolbar sit above the editor -->
+        <!-- Auto-summary banner when consolidation has run on this task. -->
+        <div v-if="isBodyAutoMaintained" class="auto-summary-banner-editor">
+          <span class="auto-summary-icon" aria-hidden="true">✦</span>
+          Auto-summarized from work logs.
+          <button
+            type="button"
+            class="btn-reconsolidate"
+            :disabled="reconsolidating"
+            @click="reconsolidate"
+          >
+            {{ reconsolidating ? "Re-consolidating…" : "Re-consolidate" }}
+          </button>
+        </div>
+
+        <!-- Write / Preview tabs + toolbar sit above the editor.
+             Write tab hidden when body is machine-maintained — use Re-consolidate
+             or edit work logs instead. -->
         <div class="body-tabs-row">
           <div class="editor-tabs">
-            <button :class="['tab', { active: !showPreview }]" @click="showPreview = false">Write</button>
-            <button :class="['tab', { active: showPreview }]" @click="showPreview = true">Preview</button>
+            <button
+              v-if="!isBodyAutoMaintained"
+              :class="['tab', { active: !showPreview }]"
+              @click="showPreview = false"
+            >Write</button>
+            <button :class="['tab', { active: showPreview || isBodyAutoMaintained }]" @click="showPreview = true">Preview</button>
           </div>
-          <MarkdownToolbar v-show="!showPreview && assist.state.value === 'idle'" :editor="tiptapEditor" />
+          <MarkdownToolbar v-show="!showPreview && !isBodyAutoMaintained && assist.state.value === 'idle'" :editor="tiptapEditor" />
         </div>
 
         <!-- Streaming preview -->
@@ -482,9 +525,14 @@ useEditorGuards(dirty, save);
           <DiffView :diff="assist.diff.value" class="main-diff" />
         </template>
 
-        <!-- Normal: editor or preview -->
+        <!-- Normal: editor or preview. When body is machine-maintained,
+             always render the preview (read-only) — never the editor. -->
         <template v-else>
-          <div v-show="!showPreview" class="body-editor-wrap">
+          <div
+            v-if="!isBodyAutoMaintained"
+            v-show="!showPreview"
+            class="body-editor-wrap"
+          >
             <TiptapEditor
               ref="editorRef"
               :modelValue="body"
@@ -494,7 +542,11 @@ useEditorGuards(dirty, save);
               @escape="titleRef?.focus()"
             />
           </div>
-          <div v-show="showPreview" class="preview-pane prose" v-html="renderedPreview" />
+          <div
+            v-show="showPreview || isBodyAutoMaintained"
+            class="preview-pane prose"
+            v-html="renderedPreview"
+          />
         </template>
 
         <div v-if="assist.error.value" class="assist-error">{{ assist.error.value }}</div>
@@ -1028,4 +1080,43 @@ useEditorGuards(dirty, save);
   outline: none;
   border-color: var(--color-primary, #6366f1);
 }
+
+/* ── Auto-summary banner + re-consolidate button ─────────────────────────── */
+.auto-summary-banner-editor {
+  display: flex;
+  align-items: center;
+  gap: 0.6rem;
+  padding: 0.45rem 0.7rem;
+  margin-bottom: 0.5rem;
+  font-size: 0.82rem;
+  font-style: italic;
+  color: var(--color-text-muted, rgba(255, 255, 255, 0.6));
+  background: rgba(99, 102, 241, 0.06);
+  border-left: 2px solid var(--color-primary, #6366f1);
+  border-radius: var(--radius-sm, 4px);
+}
+.auto-summary-banner-editor .auto-summary-icon {
+  color: var(--color-primary, #6366f1);
+  font-style: normal;
+}
+.btn-reconsolidate {
+  margin-left: auto;
+  padding: 0.25rem 0.7rem;
+  font-size: 0.78rem;
+  font-style: normal;
+  color: inherit;
+  background: transparent;
+  border: 1px solid var(--color-border, rgba(255, 255, 255, 0.12));
+  border-radius: 999px;
+  cursor: pointer;
+  transition: background 120ms ease;
+}
+.btn-reconsolidate:hover:not(:disabled) {
+  background: rgba(99, 102, 241, 0.12);
+  border-color: var(--color-primary, #6366f1);
+}
+.btn-reconsolidate:disabled {
+  opacity: 0.5;
+  cursor: progress;
+}
 </style>