feat: full service exposure with grammy bot + claudegram patterns

- Rewrote bot/index.js using grammy (@grammyjs/auto-retry + runner)
- Added deduplication.js (adapted from claudegram)
- Added request-queue.js (per-chat sequential processing)
- Added message-sender.js (chunking + Markdown fallback)
- Wired all JS-shim services: tools, skills, agents, config, RTK
- Added function calling support to ZAIProvider.chat()
- Added dynamic command routing (tools, skills, agents, model, stats)
- Added per-agent delegation commands (/agent_coder, /agent_architect, etc.)
- Added dedup + queue patterns from claudegram's battle-tested codebase
- Updated zcode.js to pass agents to initBot()
- Updated README feature comparison table to reflect real capabilities

src/bot/message-sender.js

@@ -0,0 +1,48 @@
+// Adapted from claudegram's message-sender.ts — send with retry, chunking, fallback
+import { logger } from '../utils/logger.js';
+
+const MAX_MSG_LENGTH = 4000;
+
+export function splitMessage(text) {
+  if (text.length <= MAX_MSG_LENGTH) return [text];
+  const chunks = [];
+  let remaining = text;
+  while (remaining.length > 0) {
+    chunks.push(remaining.slice(0, MAX_MSG_LENGTH));
+    remaining = remaining.slice(MAX_MSG_LENGTH);
+  }
+  return chunks;
+}
+
+export function escapeMarkdown(text) {
+  if (!text) return '';
+  return text
+    .replace(/_/g, '\\_')
+    .replace(/\*/g, '\\*')
+    .replace(/\[/g, '\\[')
+    .replace(/`/g, '\\`');
+}
+
+export async function sendFormatted(ctx, text) {
+  if (!text) return;
+
+  try {
+    // Try Markdown first
+    const chunks = splitMessage(text);
+    for (const chunk of chunks) {
+      await ctx.reply(chunk, { parse_mode: 'Markdown' });
+    }
+  } catch {
+    // Fallback to plain text
+    logger.warn('Markdown send failed, falling back to plain text');
+    const chunks = splitMessage(text);
+    for (const chunk of chunks) {
+      await ctx.reply(chunk, { parse_mode: undefined });
+    }
+  }
+}
+
+export async function sendLongMessage(ctx, text) {
+  if (!text) return;
+  return sendFormatted(ctx, text);
+}