Add tool confirmation UI with Accept/Decline for write operations

Before executing any write tool (create/update/delete), the backend now
pauses with an asyncio.Future and emits a tool_pending SSE event. The
frontend displays a ToolConfirmCard with Accept and Decline buttons.
Clicking Accept resolves the Future and proceeds; Decline records a
declined tool_call chip and falls through to regular streaming. Typing
single-word yes/no responses (e.g. "yes", "cancel") also works as
confirmation. 120s timeout auto-declines if no response.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/stores/chat.ts

@@ -17,6 +17,7 @@ import type {
   OllamaStatus,
   SendMessageResponse,
   ToolCallRecord,
+  ToolPendingRecord,
 } from "@/types/chat";
 
 export const useChatStore = defineStore("chat", () => {
@@ -28,6 +29,7 @@ export const useChatStore = defineStore("chat", () => {
   const streamingContent = ref("");
   const streamingToolCalls = ref<ToolCallRecord[]>([]);
   const streamingStatus = ref("");
+  const streamingPendingTool = ref<ToolPendingRecord | null>(null);
   const lastContextMeta = ref<ContextMeta | null>(null);
   const ollamaStatus = ref<"checking" | "available" | "unavailable">("checking");
   const modelStatus = ref<"checking" | "loaded" | "cold" | "not_found">("checking");
@@ -124,6 +126,22 @@ export const useChatStore = defineStore("chat", () => {
     const convId = currentConversation.value.id;
     lastContextMeta.value = null;
 
+    // If a write tool is waiting for confirmation, intercept single-word yes/no
+    // responses rather than sending them as a new message.
+    if (streamingPendingTool.value) {
+      const lower = content.trim().toLowerCase();
+      const YES = new Set(["yes", "y", "ok", "sure", "proceed", "accept", "confirm", "do it", "go ahead", "yeah", "yep"]);
+      const NO = new Set(["no", "n", "cancel", "decline", "stop", "nope", "abort", "don't"]);
+      if (YES.has(lower)) {
+        await confirmTool(true);
+        return;
+      }
+      if (NO.has(lower)) {
+        await confirmTool(false);
+        return;
+      }
+    }
+
     // Add optimistic user message
     const userMsg: Message = {
       id: -Date.now(), // Temporary ID
@@ -188,7 +206,12 @@ export const useChatStore = defineStore("chat", () => {
             streamingContent.value += event.data.chunk as string;
             streamingStatus.value = "";
             break;
+          case "tool_pending":
+            streamingPendingTool.value = event.data.tool_pending as ToolPendingRecord;
+            break;
           case "tool_call":
+            // Receiving a tool_call clears the pending confirmation card
+            streamingPendingTool.value = null;
             streamingToolCalls.value = [
               ...streamingToolCalls.value,
               event.data.tool_call as ToolCallRecord,
@@ -215,6 +238,7 @@ export const useChatStore = defineStore("chat", () => {
               streamingContent.value = "";
               streamingToolCalls.value = [];
               streamingStatus.value = "";
+              streamingPendingTool.value = null;
               streaming.value = false;
 
               // Update conversation in list
@@ -231,6 +255,7 @@ export const useChatStore = defineStore("chat", () => {
             streamingContent.value = "";
             streamingToolCalls.value = [];
             streamingStatus.value = "";
+            streamingPendingTool.value = null;
             useToastStore().show(
               "Chat error: " + (event.data.error as string),
               "error",
@@ -269,6 +294,19 @@ export const useChatStore = defineStore("chat", () => {
     streamingContent.value = "";
     streamingToolCalls.value = [];
     streamingStatus.value = "";
+    streamingPendingTool.value = null;
+  }
+
+  async function confirmTool(confirmed: boolean) {
+    const convId = currentConversation.value?.id;
+    if (!convId) return;
+    // Optimistically clear so buttons disappear immediately
+    streamingPendingTool.value = null;
+    try {
+      await apiPost(`/api/chat/conversations/${convId}/generation/confirm`, { confirmed });
+    } catch {
+      // Server will auto-decline on timeout — no action needed
+    }
   }
 
   async function cancelGeneration() {
@@ -353,6 +391,7 @@ export const useChatStore = defineStore("chat", () => {
     streamingContent,
     streamingToolCalls,
     streamingStatus,
+    streamingPendingTool,
     lastContextMeta,
     ollamaStatus,
     modelStatus,
@@ -364,6 +403,7 @@ export const useChatStore = defineStore("chat", () => {
     deleteConversation,
     updateTitle,
     sendMessage,
+    confirmTool,
     cancelGeneration,
     saveMessageAsNote,
     summarizeAsNote,