feat(chat): add guest chat mode for unauthenticated users

- Add POST /api/chat/guest endpoint (no auth required)
- Add proxyGuestChat() method using configurable LLM endpoint
- Add streamGuestChat() function to frontend chat API
- Modify useChat to fall back to guest mode on auth errors (403/401)
- Remove !user check from ChatInput disabled prop
- Configure guest LLM via env vars: GUEST_LLM_URL, GUEST_LLM_API_KEY, GUEST_LLM_MODEL
- Default guest LLM: http://10.1.1.42:11434/v1 (Ollama) with llama3.2 model

apps/api/src/chat-proxy/chat-proxy.service.ts

@@ -4,11 +4,14 @@ import {
   Logger,
   ServiceUnavailableException,
 } from "@nestjs/common";
+import { ConfigService } from "@nestjs/config";
 import { ContainerLifecycleService } from "../container-lifecycle/container-lifecycle.service";
 import { PrismaService } from "../prisma/prisma.service";
 import type { ChatMessage } from "./chat-proxy.dto";
 
 const DEFAULT_OPENCLAW_MODEL = "openclaw:default";
+const DEFAULT_GUEST_LLM_URL = "http://10.1.1.42:11434/v1";
+const DEFAULT_GUEST_LLM_MODEL = "llama3.2";
 
 interface ContainerConnection {
   url: string;
@@ -21,7 +24,8 @@ export class ChatProxyService {
 
   constructor(
     private readonly prisma: PrismaService,
-    private readonly containerLifecycle: ContainerLifecycleService
+    private readonly containerLifecycle: ContainerLifecycleService,
+    private readonly config: ConfigService
   ) {}
 
   // Get the user's OpenClaw container URL and mark it active.
@@ -79,6 +83,68 @@ export class ChatProxyService {
     }
   }
 
+  /**
+   * Proxy guest chat request to configured LLM endpoint.
+   * Uses environment variables for configuration:
+   * - GUEST_LLM_URL: OpenAI-compatible endpoint URL
+   * - GUEST_LLM_API_KEY: API key (optional, for cloud providers)
+   * - GUEST_LLM_MODEL: Model name to use
+   */
+  async proxyGuestChat(
+    messages: ChatMessage[],
+    signal?: AbortSignal
+  ): Promise<Response> {
+    const llmUrl = this.config.get<string>("GUEST_LLM_URL") ?? DEFAULT_GUEST_LLM_URL;
+    const llmApiKey = this.config.get<string>("GUEST_LLM_API_KEY");
+    const llmModel = this.config.get<string>("GUEST_LLM_MODEL") ?? DEFAULT_GUEST_LLM_MODEL;
+
+    const headers: Record<string, string> = {
+      "Content-Type": "application/json",
+    };
+
+    if (llmApiKey) {
+      headers["Authorization"] = `Bearer ${llmApiKey}`;
+    }
+
+    const requestInit: RequestInit = {
+      method: "POST",
+      headers,
+      body: JSON.stringify({
+        messages,
+        model: llmModel,
+        stream: true,
+      }),
+    };
+
+    if (signal) {
+      requestInit.signal = signal;
+    }
+
+    try {
+      this.logger.debug(`Guest chat proxying to ${llmUrl} with model ${llmModel}`);
+      const response = await fetch(`${llmUrl}/chat/completions`, requestInit);
+
+      if (!response.ok) {
+        const detail = await this.readResponseText(response);
+        const status = `${String(response.status)} ${response.statusText}`.trim();
+        this.logger.warn(
+          detail ? `Guest LLM returned ${status}: ${detail}` : `Guest LLM returned ${status}`
+        );
+        throw new BadGatewayException(`Guest LLM returned ${status}`);
+      }
+
+      return response;
+    } catch (error: unknown) {
+      if (error instanceof BadGatewayException) {
+        throw error;
+      }
+
+      const message = error instanceof Error ? error.message : String(error);
+      this.logger.warn(`Failed to proxy guest chat request: ${message}`);
+      throw new ServiceUnavailableException("Failed to proxy guest chat to LLM");
+    }
+  }
+
   private async getContainerConnection(userId: string): Promise<ContainerConnection> {
     const connection = await this.containerLifecycle.ensureRunning(userId);
     await this.containerLifecycle.touch(userId);