AI chat panel with Edit/Chat modes + verify dropdown

- AI chat panel at bottom of editor (all 3 modes)
- Edit mode: AI modifies document directly (no explanations)
- Chat mode: AI answers questions about the document
- Verify dropdown: Spec Review, Grammar & Spelling, Summary
- Enter sends, Shift+Enter for newline
- /api/ai/chat endpoint with edit/chat system prompts
- Grammar and spec verify actions added to /api/ai/generate

frontend/src/App.vue

@@ -119,6 +119,30 @@
           <p v-else style="color:#6c7086;font-style:italic">Preview will appear here...</p>
         </div>
       </div>
+      <!-- AI Chat Panel -->
+      <div class="ai-chat-panel" v-if="currentFile">
+        <div class="ai-chat-modes">
+          <button :class="{active: aiChatMode === 'edit'}" @click="aiChatMode = 'edit'">Edit</button>
+          <button :class="{active: aiChatMode === 'chat'}" @click="aiChatMode = 'chat'">Chat</button>
+          <select v-model="aiVerifyType" @change="runVerify" class="ai-verify-select">
+            <option value="" disabled>Verify ▾</option>
+            <option value="spec">Spec Review</option>
+            <option value="grammar">Grammar & Spelling</option>
+            <option value="summary">Summary</option>
+          </select>
+          <span v-if="aiChatLoading" class="ai-loading">⏳</span>
+        </div>
+        <div class="ai-chat-output" v-if="aiChatResponse" v-html="renderMarkdown(aiChatResponse)"></div>
+        <div class="ai-chat-input">
+          <textarea
+            v-model="aiChatInput"
+            @keydown="aiChatKeydown"
+            placeholder="Ask AI to edit or chat... (Enter to send, Shift+Enter for newline)"
+            rows="2"
+          ></textarea>
+          <button @click="sendAiChat" class="ai-send-btn">Send</button>
+        </div>
+      </div>
       <!-- History Panel -->
       <div class="history-panel" v-if="showHistory">
         <div class="panel-header">
@@ -943,6 +967,12 @@ async function shareFile() {
 
 // ─── AI ──────────────────────────────────────────────────────────────────────
 
+const aiChatMode = ref('edit')
+const aiChatInput = ref('')
+const aiChatResponse = ref('')
+const aiChatLoading = ref(false)
+const aiVerifyType = ref('')
+
 async function aiVerify() {
   if (!currentFile.value) return
   aiResult.value = 'Verifying...'
@@ -954,6 +984,55 @@ async function aiVerify() {
   }
 }
 
+async function runVerify() {
+  if (!aiVerifyType.value || !currentFile.value) return
+  aiChatLoading.value = true
+  aiChatResponse.value = ''
+  try {
+    const res = await api('/api/ai/generate', { path: currentFile.value, action: aiVerifyType.value })
+    aiChatResponse.value = res.result || res.feedback || 'No response'
+  } catch (e) {
+    aiChatResponse.value = 'AI request failed.'
+  }
+  aiChatLoading.value = false
+  aiVerifyType.value = ''
+}
+
+function aiChatKeydown(e) {
+  if (e.key === 'Enter' && !e.shiftKey) {
+    e.preventDefault()
+    sendAiChat()
+  }
+}
+
+async function sendAiChat() {
+  const msg = aiChatInput.value.trim()
+  if (!msg) return
+  aiChatLoading.value = true
+  aiChatResponse.value = ''
+  aiChatInput.value = ''
+
+  const action = aiChatMode.value === 'edit' ? 'edit' : 'chat'
+  try {
+    const res = await api('/api/ai/chat', {
+      path: currentFile.value,
+      content: content.value,
+      message: msg,
+      mode: action,
+    })
+    if (action === 'edit' && res.content) {
+      content.value = res.content
+      isDirty.value = true
+      aiChatResponse.value = 'Document updated.'
+    } else {
+      aiChatResponse.value = res.result || res.content || 'No response'
+    }
+  } catch (e) {
+    aiChatResponse.value = 'AI request failed. Check MH_AI_ENDPOINT.'
+  }
+  aiChatLoading.value = false
+}
+
 // ─── Collab ──────────────────────────────────────────────────────────────────
 
 function toggleCollab() {
@@ -1465,6 +1544,85 @@ body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; b
 }
 .git-btn.dirty { border-color: var(--danger); }
 
+/* ─── AI Chat Panel ───────────────────────────────────────────────────────── */
+
+.ai-chat-panel {
+  height: 15%;
+  min-height: 100px;
+  max-height: 200px;
+  border-top: 1px solid var(--border);
+  display: flex;
+  flex-direction: column;
+  background: var(--bg-secondary);
+}
+.ai-chat-modes {
+  display: flex;
+  gap: 4px;
+  padding: 4px 8px;
+  align-items: center;
+  border-bottom: 1px solid var(--border);
+}
+.ai-chat-modes button {
+  background: transparent;
+  border: 1px solid var(--border);
+  color: var(--text-muted);
+  padding: 2px 10px;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 12px;
+}
+.ai-chat-modes button.active {
+  background: var(--accent);
+  color: var(--bg-primary);
+  border-color: var(--accent);
+}
+.ai-verify-select {
+  background: var(--bg-primary);
+  border: 1px solid var(--border);
+  color: var(--text);
+  padding: 2px 6px;
+  border-radius: 4px;
+  font-size: 12px;
+  cursor: pointer;
+}
+.ai-loading { font-size: 12px; }
+.ai-chat-output {
+  flex: 1;
+  overflow-y: auto;
+  padding: 6px 10px;
+  font-size: 12px;
+  line-height: 1.5;
+  color: var(--text-muted);
+}
+.ai-chat-output p { margin: 0 0 6px; }
+.ai-chat-input {
+  display: flex;
+  gap: 4px;
+  padding: 4px 8px;
+  border-top: 1px solid var(--border);
+}
+.ai-chat-input textarea {
+  flex: 1;
+  background: var(--bg-primary);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text);
+  padding: 4px 8px;
+  font-size: 12px;
+  font-family: inherit;
+  resize: none;
+  outline: none;
+}
+.ai-send-btn {
+  background: var(--accent);
+  color: var(--bg-primary);
+  border: none;
+  border-radius: 4px;
+  padding: 4px 12px;
+  cursor: pointer;
+  font-size: 12px;
+}
+
 .history-panel, .share-dialog, .ai-panel {
   position: absolute;
   right: 0;

internal/api/ai.go

@@ -98,12 +98,21 @@ func (s *Server) handleAIGenerate(w http.ResponseWriter, r *http.Request) {
 
 	systemPrompt := "You are a helpful assistant. Respond in markdown."
 	switch req.Action {
-	case "summarize":
+	case "summarize", "summary":
 		systemPrompt = "Summarize the following text concisely in markdown."
 	case "prompt":
 		systemPrompt = "Generate a detailed AI prompt based on the following specification. The prompt should instruct an AI coding agent to implement the project."
 	case "expand":
 		systemPrompt = "Expand on the following text with more detail, examples, and explanations. Respond in markdown."
+	case "grammar":
+		systemPrompt = "Review the following text for grammar and spelling errors. List each error with the correction. Be concise. Format as a markdown list."
+	case "spec":
+		systemPrompt = `You are a technical reviewer. Review the following specification document for:
+1. Completeness - are there missing details needed to implement this?
+2. Ambiguities - are there unclear requirements?
+3. Feasibility - is this technically achievable?
+4. Suggestions - any improvements?
+Respond with a structured review. End with a clear verdict: READY TO BUILD or NEEDS REVISION.`
 	}
 
 	response, err := callLLM(aiEndpoint, aiKey, aiModel, systemPrompt, inputText)
@@ -118,7 +127,58 @@ func (s *Server) handleAIGenerate(w http.ResponseWriter, r *http.Request) {
 		files.WriteFile(s.dataDir, userID, filename, response)
 	}
 
-	writeJSON(w, 200, map[string]string{"output": response})
+	writeJSON(w, 200, map[string]string{"result": response})
+}
+
+func (s *Server) handleAIChat(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Path    string `json:"path"`
+		Content string `json:"content"`
+		Message string `json:"message"`
+		Mode    string `json:"mode"` // "edit" or "chat"
+	}
+	if err := decodeBody(r, &req); err != nil || req.Message == "" {
+		writeJSON(w, 400, map[string]string{"error": "message required"})
+		return
+	}
+
+	aiEndpoint := os.Getenv("MH_AI_ENDPOINT")
+	aiKey := os.Getenv("MH_AI_API_KEY")
+	aiModel := os.Getenv("MH_AI_MODEL")
+	if aiEndpoint == "" {
+		writeJSON(w, 500, map[string]string{"error": "AI endpoint not configured"})
+		return
+	}
+	if aiModel == "" {
+		aiModel = "gpt-4"
+	}
+
+	var systemPrompt string
+	var userMsg string
+
+	if req.Mode == "edit" {
+		systemPrompt = `You are a document editor. The user will give you a markdown document and an instruction.
+Apply the instruction to the document and return ONLY the complete updated document.
+Do not add explanations, comments, or markdown code fences around the output.
+Preserve the document's existing style and formatting.`
+		userMsg = "Document:\n\n" + req.Content + "\n\nInstruction: " + req.Message
+	} else {
+		systemPrompt = `You are a helpful writing assistant. The user has a markdown document open and is asking a question about it.
+Answer concisely in markdown. Reference the document content when relevant.`
+		userMsg = "Document:\n\n" + req.Content + "\n\nQuestion: " + req.Message
+	}
+
+	response, err := callLLM(aiEndpoint, aiKey, aiModel, systemPrompt, userMsg)
+	if err != nil {
+		writeJSON(w, 500, map[string]string{"error": "AI call failed: " + err.Error()})
+		return
+	}
+
+	if req.Mode == "edit" {
+		writeJSON(w, 200, map[string]string{"content": response})
+	} else {
+		writeJSON(w, 200, map[string]string{"result": response})
+	}
 }
 
 func callLLM(endpoint, apiKey, model, systemPrompt, userContent string) (string, error) {

internal/api/router.go

@@ -65,6 +65,7 @@ func NewRouter(db *sql.DB, dataDir, secret string) http.Handler {
 	// AI
 	mux.HandleFunc("POST /api/ai/verify", s.requireAuth(s.handleAIVerify))
 	mux.HandleFunc("POST /api/ai/generate", s.requireAuth(s.handleAIGenerate))
+	mux.HandleFunc("POST /api/ai/chat", s.requireAuth(s.handleAIChat))
 
 	// Build jobs
 	mux.HandleFunc("POST /api/build/submit", s.requireAuth(s.handleBuildSubmit))