fix: rename KV binding to CLAUDE_STATUS and fix threadId nullish check

- Rename KV binding SUBSCRIBERS → CLAUDE_STATUS for consistent naming
- Fix || null → ?? null to preserve threadId 0 (General topic)
- Update KV namespace creation command in README

src/bot-commands.js

@@ -18,7 +18,7 @@ import {
 function getChatTarget(ctx) {
   return {
     chatId: ctx.chat.id,
-    threadId: ctx.message?.message_thread_id || null,
+    threadId: ctx.message?.message_thread_id ?? null,
   };
 }
 
@@ -27,7 +27,7 @@ function getChatTarget(ctx) {
  */
 export async function handleTelegramWebhook(c) {
   const bot = new Bot(c.env.BOT_TOKEN);
-  const kv = c.env.SUBSCRIBERS;
+  const kv = c.env.CLAUDE_STATUS;
 
   bot.command("start", async (ctx) => {
     const { chatId, threadId } = getChatTarget(ctx);

src/queue-consumer.js

@@ -36,7 +36,7 @@ export async function handleQueue(batch, env) {
         msg.ack();
       } else if (res.status === 403 || res.status === 400) {
         // Bot blocked or chat not found — auto-remove subscriber
-        await removeSubscriber(env.SUBSCRIBERS, chatId, threadId);
+        await removeSubscriber(env.CLAUDE_STATUS, chatId, threadId);
         msg.ack();
       } else if (res.status === 429) {
         // Rate limited — let queue retry later

src/statuspage-webhook.js

@@ -69,7 +69,7 @@ export async function handleStatuspageWebhook(c) {
   }
 
   // Get filtered subscribers
-  const subscribers = await getSubscribersByType(c.env.SUBSCRIBERS, category);
+  const subscribers = await getSubscribersByType(c.env.CLAUDE_STATUS, category);
 
   // Enqueue messages for fan-out via CF Queues (batch for performance)
   const messages = subscribers.map(({ chatId, threadId }) => ({