feat: add Telegram connector package for mesh-to-chat bridging

Introduces @claudemesh/connector-telegram — a standalone bridge process
that joins a mesh as peerType: "connector" and relays messages
bidirectionally between a Telegram chat and mesh peers via long polling.

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

packages/connector-telegram/src/bridge.ts

@@ -0,0 +1,96 @@
+/**
+ * Bidirectional bridge between Telegram and a claudemesh mesh.
+ *
+ * Telegram -> Mesh: incoming Telegram messages are formatted as
+ *   "[TelegramUser] message" and broadcast to the mesh.
+ *
+ * Mesh -> Telegram: inbound mesh pushes are formatted as
+ *   "[MeshPeerName] message" and posted to the Telegram chat.
+ */
+
+import type { TelegramClient, TelegramMessage } from "./telegram.js";
+import type { MeshClient, InboundPush } from "./mesh-client.js";
+
+export class Bridge {
+  constructor(
+    private telegram: TelegramClient,
+    private mesh: MeshClient,
+  ) {}
+
+  /** Wire up both directions. Call once after both clients are connected. */
+  start(): void {
+    // Telegram -> Mesh
+    this.telegram.onMessage((msg: TelegramMessage) => {
+      this.handleTelegramMessage(msg);
+    });
+
+    // Mesh -> Telegram
+    this.mesh.onPush((push: InboundPush) => {
+      this.handleMeshPush(push);
+    });
+
+    console.log("[bridge] relay active");
+  }
+
+  private handleTelegramMessage(msg: TelegramMessage): void {
+    if (!msg.text) {
+      // Skip non-text messages (photos, stickers, etc.)
+      const type = msg.from
+        ? "non-text content"
+        : "system message";
+      console.log(`[bridge] skipping ${type} from Telegram`);
+      return;
+    }
+
+    const senderName = formatTelegramSender(msg);
+    const meshMessage = `[${senderName}] ${msg.text}`;
+
+    console.log(`[bridge] tg->mesh: ${meshMessage.slice(0, 80)}...`);
+
+    // Broadcast to all mesh peers
+    this.mesh.send("*", meshMessage).catch((err) => {
+      console.error(`[bridge] failed to relay to mesh:`, err);
+    });
+  }
+
+  private handleMeshPush(push: InboundPush): void {
+    // Decode the message content
+    const plaintext = push.plaintext ?? tryDecodeBase64(push.ciphertext);
+    if (!plaintext) return;
+
+    // Skip messages that originated from this connector (prevent echo)
+    if (push.senderPubkey === this.mesh.pubkey) return;
+
+    // Find the sender's display name from the push metadata
+    const senderName = push.senderDisplayName || push.senderPubkey.slice(0, 8);
+    const telegramMessage = `<b>[${escapeHtml(senderName)}]</b> ${escapeHtml(plaintext)}`;
+
+    console.log(`[bridge] mesh->tg: [${senderName}] ${plaintext.slice(0, 60)}...`);
+
+    this.telegram.sendMessage(telegramMessage).catch((err) => {
+      console.error(`[bridge] failed to relay to Telegram:`, err);
+    });
+  }
+}
+
+function formatTelegramSender(msg: TelegramMessage): string {
+  if (!msg.from) return "Unknown";
+  const parts = [msg.from.first_name];
+  if (msg.from.last_name) parts.push(msg.from.last_name);
+  return parts.join(" ");
+}
+
+function tryDecodeBase64(b64: string): string | null {
+  try {
+    return Buffer.from(b64, "base64").toString("utf-8");
+  } catch {
+    return null;
+  }
+}
+
+function escapeHtml(text: string): string {
+  return text
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;");
+}