feat(ui): add Maintain step with graph visualization

Move the graph view from a Verify-tab (where it sat post-analysis, off
the main flow) to a dedicated Maintain step after Ingest, so the graph
result is visible at the natural end of the Configure → Verify →
Prepare → Ingest → Maintain pipeline.

- StudioPage: new 'maintain' mode toggle + panel rendering GraphView
- ResultTabs: remove obsolete graph tab
- i18n: add studio.maintain (fr + en)
- GraphView: fix init order — flip loading off and await nextTick before
  renderGraph so the canvas <div> is mounted when cytoscape reads its
  container ref (previous code bailed silently on null ref)

frontend/src/features/analysis/ui/GraphView.vue

@@ -33,7 +33,7 @@
 </template>
 
 <script setup lang="ts">
-import { onMounted, onBeforeUnmount, ref, watch } from 'vue'
+import { onMounted, onBeforeUnmount, ref, watch, nextTick } from 'vue'
 import { useI18n } from '../../../shared/i18n'
 import { fetchDocumentGraph, type GraphPayload } from '../graphApi'
 
@@ -90,11 +90,12 @@ async function load(): Promise<void> {
     payload.value = await fetchDocumentGraph(props.docId)
     if (!payload.value.nodes.length) {
       empty.value = true
-    } else {
-      // Wait for template to render the canvas before initializing Cytoscape.
-      await new Promise((r) => requestAnimationFrame(r))
-      await renderGraph()
+      return
     }
+    // Flip loading off so the canvas <div> mounts, then wait a tick before init.
+    loading.value = false
+    await nextTick()
+    await renderGraph()
   } catch (e) {
     error.value = (e as Error).message || 'Failed to load graph'
     console.error('Failed to load graph', e)

frontend/src/features/analysis/ui/ResultTabs.vue

@@ -106,12 +106,6 @@
 
       <!-- IMAGES -->
       <ImageGallery v-else-if="activeTab === 'images'" :pages="currentPageAsArray" />
-
-      <!-- GRAPH -->
-      <GraphView
-        v-else-if="activeTab === 'graph'"
-        :doc-id="store.currentAnalysis?.documentId ?? null"
-      />
     </div>
   </div>
   <div v-else-if="store.currentAnalysis?.status === 'RUNNING'" class="result-placeholder">
@@ -199,7 +193,6 @@ import { ref, computed, reactive } from 'vue'
 import { useAnalysisStore } from '../store'
 import MarkdownViewer from './MarkdownViewer.vue'
 import ImageGallery from './ImageGallery.vue'
-import GraphView from './GraphView.vue'
 import { useI18n } from '../../../shared/i18n'
 import type { PageElement } from '../../../shared/types'
 
@@ -230,7 +223,6 @@ const tabs = computed(() => [
   { id: 'elements', label: t('results.elements') },
   { id: 'markdown', label: t('results.markdown') },
   { id: 'images', label: t('results.images') },
-  { id: 'graph', label: t('results.graph') },
 ])
 
 const totalPages = computed(() => store.currentPages.length)

frontend/src/pages/StudioPage.vue

@@ -84,6 +84,27 @@
             </svg>
             {{ t('studio.ingest') }}
           </button>
+          <button
+            v-if="chunkingEnabled && ingestionEnabled && ingestionStore.available"
+            class="toggle-btn"
+            data-e2e="toggle-btn maintain-btn"
+            :class="{ active: mode === 'maintain' }"
+            @click="mode = 'maintain'"
+            :disabled="!analysisStore.currentAnalysis"
+          >
+            <svg class="toggle-icon" viewBox="0 0 20 20" fill="currentColor">
+              <path
+                d="M10 3.5a6.5 6.5 0 100 13 6.5 6.5 0 000-13zM6 10a4 4 0 118 0 4 4 0 01-8 0zm4-2a2 2 0 100 4 2 2 0 000-4z"
+              />
+              <path
+                d="M10 1v2M10 17v2M1 10h2M17 10h2M3.5 3.5l1.4 1.4M15.1 15.1l1.4 1.4M3.5 16.5l1.4-1.4M15.1 4.9l1.4-1.4"
+                stroke="currentColor"
+                stroke-width="1.5"
+                fill="none"
+              />
+            </svg>
+            {{ t('studio.maintain') }}
+          </button>
         </div>
       </div>
       <div class="topbar-actions">
@@ -475,6 +496,11 @@
             :chunk-count="analysisStore.currentChunks?.length ?? 0"
           />
         </div>
+
+        <!-- MAINTAIN MODE -->
+        <div v-if="mode === 'maintain'" class="maintain-panel">
+          <GraphView :doc-id="analysisStore.currentAnalysis?.documentId ?? null" />
+        </div>
       </div>
     </div>
   </div>
@@ -489,6 +515,7 @@ import { useIngestionStore } from '../features/ingestion/store'
 import { DocumentUpload, DocumentList } from '../features/document/index'
 import { ResultTabs } from '../features/analysis/index'
 import BboxOverlay from '../features/analysis/ui/BboxOverlay.vue'
+import GraphView from '../features/analysis/ui/GraphView.vue'
 import { ChunkPanel } from '../features/chunking'
 import { IngestPanel } from '../features/ingestion'
 import { useFeatureFlag } from '../features/feature-flags'
@@ -1404,10 +1431,11 @@ onBeforeUnmount(() => {
   padding-top: 16px;
 }
 
-/* Verify / Prepare / Ingest panels */
+/* Verify / Prepare / Ingest / Maintain panels */
 .verify-panel,
 .prepare-panel,
-.ingest-panel-wrapper {
+.ingest-panel-wrapper,
+.maintain-panel {
   height: 100%;
   overflow: hidden;
   display: flex;

frontend/src/shared/i18n.ts

@@ -114,6 +114,7 @@ const messages: Messages = {
     // Chunking
     'studio.prepare': 'Préparer',
     'studio.ingest': 'Ingérer',
+    'studio.maintain': 'Maintenir',
     'chunking.settings': 'Chunking',
     'chunking.chunkerType': 'Type de chunker',
     'chunking.maxTokens': 'Tokens max',
@@ -287,6 +288,7 @@ const messages: Messages = {
 
     'studio.prepare': 'Prepare',
     'studio.ingest': 'Ingest',
+    'studio.maintain': 'Maintain',
     'chunking.settings': 'Chunking',
     'chunking.chunkerType': 'Chunker type',
     'chunking.maxTokens': 'Max tokens',