feat: Slack platform + Claude-powered chat support widget

- Add Slack as customer-facing messaging platform (client, 4 MCP tools, dashboard card)
- Add /api/chat endpoint powered by Claude Haiku with SquareMCP system prompt
- Add embeddable chat-widget.js injected into all 3 sites (docs, app, www)
- Add ANTHROPIC_API_KEY, serve product/ as static files
- Update Platform type to include slack

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

src/tools.ts

@@ -14,6 +14,7 @@ import { searchTweets, getUserProfile, getUserTweets, createTweet, uploadVideoAn
 import { getUserProfile as getTikTokProfile, getCreatorInfo, createVideo, getVideoStatus } from './clients/tiktok.js';
 import { getMe as getSnapchatMe, createSnap, getAdAccounts } from './clients/snapchat.js';
 import { getPage, getPosts, createPost as createFacebookPost, createPhotoPost, createVideoPost as createFacebookVideoPost } from './clients/facebook.js';
+import { getMe as getSlackMe, getChannels as getSlackChannels, sendMessage as sendSlackMessage, getMessages as getSlackMessages } from './clients/slack.js';
 
 const ACCOUNT_PARAM = {
   account: {
@@ -443,6 +444,59 @@ export const tools: Tool[] = [
     },
   },
 
+  // ── Slack tools ──────────────────────────────────────────────
+  {
+    name: 'slack_get_me',
+    description:
+      'Verify the Slack bot is connected and return workspace info. Use to confirm credentials are working.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        account: { type: 'string', description: 'Which Slack account to use (default: "default")' },
+      },
+    },
+  },
+  {
+    name: 'slack_get_channels',
+    description:
+      'List Slack channels the bot has access to. Use to find channel IDs before sending messages.',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        limit: { type: 'number', description: 'Max channels to return (default: 100)' },
+        account: { type: 'string', description: 'Which Slack account to use (default: "default")' },
+      },
+    },
+  },
+  {
+    name: 'slack_send_message',
+    description:
+      'Send a message to a Slack channel. Uses the default channel if channel_id is omitted.',
+    inputSchema: {
+      type: 'object',
+      required: ['text'],
+      properties: {
+        channel_id: { type: 'string', description: 'Slack channel ID (e.g. C0123456). Uses default channel if omitted.' },
+        text: { type: 'string', description: 'Message text. Supports Slack mrkdwn formatting.' },
+        account: { type: 'string', description: 'Which Slack account to use (default: "default")' },
+      },
+    },
+  },
+  {
+    name: 'slack_get_messages',
+    description:
+      'Get recent messages from a Slack channel.',
+    inputSchema: {
+      type: 'object',
+      required: ['channel_id'],
+      properties: {
+        channel_id: { type: 'string', description: 'Slack channel ID' },
+        limit: { type: 'number', description: 'Max messages to return (default: 10)' },
+        account: { type: 'string', description: 'Which Slack account to use (default: "default")' },
+      },
+    },
+  },
+
   // ── Instagram tools ──────────────────────────────────────────
   {
     name: 'instagram_get_profile',
@@ -738,7 +792,7 @@ async function resolveEmailCtx(args: Record<string, unknown>, customer?: Custome
 
 const PLATFORM_PREFIXES = [
   'linkedin', 'obsidian', 'whatsapp', 'telegram', 'discord',
-  'instagram', 'twitter', 'tiktok', 'snapchat', 'facebook',
+  'instagram', 'twitter', 'tiktok', 'snapchat', 'facebook', 'slack',
 ];
 
 function toolPlatform(name: string): string {
@@ -984,6 +1038,36 @@ export async function handleToolCall(
         }, customer);
         break;
 
+      // ── Slack ───────────────────────────────────────────────────
+      case 'slack_get_me':
+        result = await getSlackMe({
+          account: args.account as string | undefined,
+        }, customer);
+        break;
+
+      case 'slack_get_channels':
+        result = await getSlackChannels({
+          limit: args.limit as number | undefined,
+          account: args.account as string | undefined,
+        }, customer);
+        break;
+
+      case 'slack_send_message':
+        result = await sendSlackMessage({
+          channel_id: args.channel_id as string | undefined,
+          text: args.text as string,
+          account: args.account as string | undefined,
+        }, customer);
+        break;
+
+      case 'slack_get_messages':
+        result = await getSlackMessages({
+          channel_id: args.channel_id as string,
+          limit: args.limit as number | undefined,
+          account: args.account as string | undefined,
+        }, customer);
+        break;
+
       // ── Instagram ───────────────────────────────────────────────
       case 'instagram_get_profile':
         result = await getInstagramProfile({