initial: webhook telegram adapter for pi with streaming replies

- webhook server with secret validation, rate limiting, body guards
- streaming replies via sendMessage + editMessageText throttled loop
- RPC session management for persistent conversations
- 15/15 tests passing

tests/streaming-reply.test.ts

@@ -0,0 +1,107 @@
+/**
+ * Tests for streaming reply logic.
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { StreamingReply } from "../src/streaming-reply.js";
+import type { TelegramAPI } from "../src/telegram-api.js";
+
+describe("streaming-reply", () => {
+  it("should throttle edits", async () => {
+    const sent: Array<{ type: string; text: string }> = [];
+    const mockApi = {
+      sendMessage: vi.fn(async (_chatId: string, text: string) => {
+        sent.push({ type: "send", text });
+        return { message_id: 1 };
+      }),
+      editMessageText: vi.fn(async (_chatId: string, _msgId: number, text: string) => {
+        sent.push({ type: "edit", text });
+      }),
+    } as unknown as TelegramAPI;
+
+    const streaming = new StreamingReply(mockApi, "123", 1, {
+      throttleMs: 100,
+      minInitialChars: 10,
+    });
+
+    streaming.update("Hello");
+    streaming.update("Hello world");
+    streaming.update("Hello world!!!");
+
+    // Wait for throttle + initial char check
+    await new Promise((resolve) => setTimeout(resolve, 150));
+
+    expect(sent.length).toBeGreaterThan(0);
+    expect(sent[0]?.type).toBe("send");
+    expect(sent[0]?.text).toContain("Hello");
+
+    await streaming.stop();
+  });
+
+  it("should track generation to prevent clobbering", () => {
+    const mockApi = {
+      sendMessage: vi.fn(async () => ({ message_id: 1 })),
+      editMessageText: vi.fn(),
+    } as unknown as TelegramAPI;
+
+    const streaming1 = new StreamingReply(mockApi, "123", 1, { throttleMs: 1000 });
+    const streaming2 = new StreamingReply(mockApi, "123", 2, { throttleMs: 1000 });
+
+    expect(streaming1.getGeneration()).toBe(1);
+    expect(streaming2.getGeneration()).toBe(2);
+    expect(streaming1.getGeneration()).not.toBe(streaming2.getGeneration());
+  });
+
+  it("should truncate text exceeding 4096 chars", async () => {
+    const sent: string[] = [];
+    const mockApi = {
+      sendMessage: vi.fn(async (_chatId: string, text: string) => {
+        sent.push(text);
+        return { message_id: 1 };
+      }),
+      editMessageText: vi.fn(),
+    } as unknown as TelegramAPI;
+
+    const streaming = new StreamingReply(mockApi, "123", 1, {
+      throttleMs: 50,
+      minInitialChars: 0,
+    });
+
+    streaming.update("x".repeat(5000));
+    await streaming.flush();
+
+    expect(sent.length).toBe(1);
+    expect(sent[0]!.length).toBe(4096);
+
+    await streaming.stop();
+  });
+
+  it("should debounce first send based on minInitialChars", async () => {
+    const sent: string[] = [];
+    const mockApi = {
+      sendMessage: vi.fn(async (_chatId: string, text: string) => {
+        sent.push(text);
+        return { message_id: 1 };
+      }),
+      editMessageText: vi.fn(),
+    } as unknown as TelegramAPI;
+
+    const streaming = new StreamingReply(mockApi, "123", 1, {
+      throttleMs: 50,
+      minInitialChars: 20,
+    });
+
+    streaming.update("Short");
+    await streaming.flush();
+
+    // Should not send yet
+    expect(sent.length).toBe(0);
+
+    streaming.update("This is now long enough to send");
+    await streaming.flush();
+
+    expect(sent.length).toBe(1);
+
+    await streaming.stop();
+  });
+});