fix: assistant IA toujours en mode agent, retrait du bouton toggle #187

- Bouton « mode agent » du panneau supprimé : l'assistant est toujours
  agent (toute requête texte part sur /api/ai/bookslm/agent, les images
  restent sur /chat multimodal). Les mutations gardent la confirmation
  two-step. Deep Research et les quick actions `agent: true` basculaient
  déjà le mode en silence : le toggle ne protégeait plus rien.
- /agent résout le provider comme /chat (req.provider brut transmis à
  l'adapter pouvait désigner un fournisseur indisponible et retomber
  silencieusement sur un autre que l'étiquette SSE affichée).
- Schémas des outils mis en cache par (scope, taille du registre) avec
  copies fraîches par appelant (~27 ms de pydantic économisées par
  requête agent/MCP).
- Aide in-app réécrite, i18n FR/EN (retrait de ai.agent_mode_*),
  tests frontend adaptés (ai.test.mjs 100/100) + non-régression pytest
  (provider résolu, cache sûr).

frontend/index.html

@@ -4674,9 +4674,9 @@
                                     conversation.
                                 </li>
                                 <li data-i18n="help.assistant_agent">
-                                    Le bouton « mode agent » active les outils (lire, lister,
-                                    chercher) ; les actions de modification demandent une
-                                    confirmation avec aperçu des changements.
+                                    L'assistant utilise toujours ses outils (lire, lister,
+                                    chercher, modifier) ; les actions de modification demandent
+                                    une confirmation avec aperçu des changements.
                                 </li>
                                 <li data-i18n="help.assistant_agent_run">
                                     Les actions s'affichent dans le fil : l'assistant regroupe les

frontend/js/ai-quick-actions.js

@@ -46,8 +46,8 @@ export const ACTION_CATALOG = Object.freeze([
   { id: 'checklist', cat: 'structure', icon: 'list-checks', labelKey: 'qa.checklist', promptKey: 'qa.checklist.prompt' },
   { id: 'plan', cat: 'structure', icon: 'list-ordered', labelKey: 'qa.plan', promptKey: 'qa.plan.prompt' },
   { id: 'memo', cat: 'structure', icon: 'scroll-text', labelKey: 'qa.memo', promptKey: 'qa.memo.prompt' },
-  { id: 'frontmatter', cat: 'structure', icon: 'braces', labelKey: 'qa.frontmatter', promptKey: 'qa.frontmatter.prompt', agent: true },
-  { id: 'frontmatter_update', cat: 'structure', icon: 'refresh-cw', labelKey: 'qa.frontmatter_update', promptKey: 'qa.frontmatter_update.prompt', agent: true },
+  { id: 'frontmatter', cat: 'structure', icon: 'braces', labelKey: 'qa.frontmatter', promptKey: 'qa.frontmatter.prompt' },
+  { id: 'frontmatter_update', cat: 'structure', icon: 'refresh-cw', labelKey: 'qa.frontmatter_update', promptKey: 'qa.frontmatter_update.prompt' },
   { id: 'backlinks', cat: 'structure', icon: 'link-2', labelKey: 'qa.backlinks', promptKey: 'qa.backlinks.prompt' },
   { id: 'sections', cat: 'structure', icon: 'heading', labelKey: 'qa.sections', promptKey: 'qa.sections.prompt' },
   // ── Code & Scripts ───────────────────────────────────────────────────

frontend/js/bookslm.js

@@ -151,9 +151,8 @@ class BooksLM {
     this._sessions = [];
     this._currentSessionId = null;
     this._pendingNewSession = false;
-    // Agent mode: routes chat through /api/ai/bookslm/agent so the model can
-    // call read/search tools and propose mutations (confirmation cards).
-    this._agentMode = this._readAgentMode();
+    // #187: the assistant is always in agent mode (tools on /agent endpoint);
+    // the former header toggle was removed — images still use the /chat path.
     // Ad-hoc context added with `@` (files/directories) and images attached
     // by paste or by mentioning an image file.
     this._adhocFiles = [];
@@ -188,33 +187,6 @@ class BooksLM {
     this._extensions = null;
   }
 
-  _readAgentMode() {
-    try {
-      return localStorage.getItem('obsigate-bookslm-agent') === 'true';
-    } catch {
-      return false;
-    }
-  }
-
-  _toggleAgentMode() {
-    this._agentMode = !this._agentMode;
-    try {
-      localStorage.setItem('obsigate-bookslm-agent', this._agentMode ? 'true' : 'false');
-    } catch { /* private mode */ }
-    this._updateAgentToggle();
-  }
-
-  _updateAgentToggle() {
-    if (!this._panel) return;
-    const btn = this._panel.querySelector('.bookslm-btn-agent');
-    if (!btn) return;
-    btn.classList.toggle('active', this._agentMode);
-    const label = this._agentMode ? t('ai.agent_mode_on') : t('ai.agent_mode_off');
-    btn.title = label;
-    btn.setAttribute('aria-label', label);
-    btn.setAttribute('aria-pressed', this._agentMode ? 'true' : 'false');
-  }
-
   // ── Public API ──────────────────────────────────────────────────────
 
   /**
@@ -966,7 +938,6 @@ class BooksLM {
         </div>
         <span class="bookslm-qa-badge hidden" data-qa-context=""></span>
         <div class="bookslm-header-actions">
-          <button class="bookslm-btn-agent" title="${t('ai.agent_mode_off')}" aria-label="${t('ai.agent_mode_off')}" aria-pressed="false"><i data-lucide="bot" style="width:16px;height:16px"></i></button>
           <button class="bookslm-btn-history" title="${t('bookslm.session_history')}" aria-label="${t('bookslm.session_history')}"><i data-lucide="history" style="width:16px;height:16px"></i></button>
           <button class="bookslm-btn-new" title="${t('bookslm.new_conversation')}" aria-label="${t('bookslm.new_conversation')}"><i data-lucide="plus" style="width:16px;height:16px"></i></button>
           <button class="bookslm-btn-export" title="${t('bookslm.export')}" aria-label="${t('bookslm.export')}"><i data-lucide="download" style="width:16px;height:16px"></i></button>
@@ -1011,7 +982,6 @@ class BooksLM {
 
     panel.querySelector('.bookslm-btn-close').addEventListener('click', () => this.close());
     panel.querySelector('.bookslm-btn-new').addEventListener('click', () => this.newConversation());
-    panel.querySelector('.bookslm-btn-agent').addEventListener('click', () => this._toggleAgentMode());
     panel.querySelector('.bookslm-btn-history').addEventListener('click', (e) => {
       e.stopPropagation();
       this._toggleHistoryMenu();
@@ -1552,10 +1522,9 @@ class BooksLM {
     if (typeof safeCreateIcons === 'function') safeCreateIcons();
   }
 
-  /** #97/#99 — Deep Research: agent tools + a skill-like chip (no composer text). */
+  /** #97/#99 — Deep Research: a skill-like chip (the agent tools are always on). */
   _startDeepResearch() {
     this._closeExtMenu();
-    if (!this._agentMode) this._toggleAgentMode();
     this._activeDeepResearch = true;
     this._renderAttachments();
     showToast(t('bookslm.deep_research_started'), 'info');
@@ -2201,15 +2170,14 @@ class BooksLM {
   }
 
   /** Immediate-send the action prompt through the composer (same path as a
-   *  typed message: skills, agent mode and images all keep working). Actions
-   *  flagged `agent` (they mutate the document) transparently switch the
-   *  assistant to agent mode first — same pattern as Deep Research. */
+   *  typed message: skills and images all keep working). #187: the assistant
+   *  is always agent mode, so the former `agent: true` quick actions need no
+   *  mode switch anymore. */
   _runQuickAction(action) {
     if (!this._panel || !action) return;
     const { prompt } = actionTexts(action);
     if (!prompt) return;
     this._closeActionDrawer();
-    if (action.agent && !this._agentMode) this._toggleAgentMode();
     const textarea = this._panel.querySelector('textarea');
     if (!textarea) return;
     textarea.value = prompt;
@@ -3253,14 +3221,15 @@ class BooksLM {
     this._saveHistory();
   }
 
-  /** POST to /chat or /agent depending on the agent-mode toggle. */
+  /** POST to /agent (always) or /chat when images are attached. */
   _postChat(payload) {
-    // Images require the plain multimodal chat endpoint (the agent loop is
+    // #187: the assistant is always agent mode — images are the only case
+    // that still needs the plain multimodal chat endpoint (the agent loop is
     // text/tool oriented).
     const hasImages = Array.isArray(payload.images) && payload.images.length > 0;
-    const endpoint = (this._agentMode && !hasImages)
-      ? '/api/ai/bookslm/agent'
-      : '/api/ai/bookslm/chat';
+    const endpoint = hasImages
+      ? '/api/ai/bookslm/chat'
+      : '/api/ai/bookslm/agent';
     const headers = { 'Content-Type': 'application/json', ...(AuthManager.getAuthHeaders() || {}) };
     return fetch(endpoint, {
       method: 'POST',