feat(pi): 交互式 pi 会话接入邮件工具（send_mail/read_inbox 等 10 个）

问题（⑧）：守护进程用 noExtensions:true 起会话，它的邮件工具只给模型在邮件
会话里用；人在 TUI 里敲的 pi 拿不到。结果是平台的建设者自己收不到邮件 ——
一个「邮件驱动」的平台，维护者只能绕到 curl + 密钥直连 Gateway 才能看收件箱。

新增 plugins/pi-mail-bridge/extension/index.ts：把同一套工具（createMailTools）
注册到交互式会话。两者是同一条 AgentMail 身份（agent pi）的两个入口，与 DSH 的
「TUI + 邮箱是同一个 Agent」一致。

密钥解析顺序（交互式 pi 的环境里没有 AGENTMAIL_*）：
  1. 进程环境
  2. AGENTMAIL_ENV_FILE（默认 /etc/agentmail/pi.env）—— 与守护进程同一把密钥，
     因此身份一致
  3. AGENTMAIL_CONFIG_DIR/agent.key 或 ~/.agentmail/agent.key
     （兼容 key 与 key_token 两种字段名；实测本机文件用的是 key_token，
      只认 key 会静默读不到）
拿不到密钥时不注册任何工具并明确告知 —— 挂一组永远 401 的工具比没有更糟。

不注册 connect_to_server：它会重写 Gateway 坐标并重新登记密钥，而交互式会话与
守护进程共用同一身份，一次 TUI 对话不该改到守护进程的配置。

为什么不会重复注册（读 SDK 实现确认，并用探针实测）：
  resource-loader.js 里 noExtensions 为真时只用 cliEnabledExtensions，
  settings.json 的 extensions 数组被排除 —— 即 noExtensions:true 只加载
  命令行 -e 传入的扩展。
  探针：noExtensions=true → 扩展数=0；false → 16 个且含 pi-mail-bridge。

deploy/install.sh 增加幂等的扩展注册步骤（写入 settings.json 的 extensions）。

验证：headless pi 实际调用 read_inbox 返回真实邮件主题；工具清单含
send_mail/read_inbox/read_mail/forward_mail/upload_attachment/download_attachment/
suggest_address/list_contacts/session_participants/read_thread（10 个），
connect_to_server 按设计排除。

plugins/dsh-mail-bridge/lib/mail-session-id.d.ts

@@ -1,3 +1,9 @@
 export declare function dshSessionIdForMail(mailSessionID: any): string;
-export declare function matchesMailSession(dshSessionId: any, mailSessionID: any): boolean;
-export declare function pickMailSession(dshSessionIds: any[] | undefined, mailSessionID: any): string | undefined;
+export declare function matchesMailSession(
+	dshSessionId: any,
+	mailSessionID: any,
+): boolean;
+export declare function pickMailSession(
+	dshSessionIds: any[] | undefined,
+	mailSessionID: any,
+): string | undefined;

plugins/dsh-mail-bridge/lib/mail-session-id.js

@@ -24,7 +24,7 @@
 
 /** 首次尝试使用的 DSH 会话 id。 */
 export function dshSessionIdForMail(mailSessionID) {
-  return `mail-${String(mailSessionID ?? '')}`;
+	return `mail-${String(mailSessionID ?? "")}`;
 }
 
 /**
@@ -35,12 +35,12 @@ export function dshSessionIdForMail(mailSessionID) {
  * @returns {boolean}
  */
 export function matchesMailSession(dshSessionId, mailSessionID) {
-  const id = String(dshSessionId ?? '');
-  const base = dshSessionIdForMail(mailSessionID);
-  if (id === base) return true;
-  // 模型降级重试：mail-<id>-r1 / -r2 / …
-  const suffix = id.startsWith(`${base}-r`) ? id.slice(base.length + 2) : '';
-  return suffix.length > 0 && /^\d+$/.test(suffix);
+	const id = String(dshSessionId ?? "");
+	const base = dshSessionIdForMail(mailSessionID);
+	if (id === base) return true;
+	// 模型降级重试：mail-<id>-r1 / -r2 / …
+	const suffix = id.startsWith(`${base}-r`) ? id.slice(base.length + 2) : "";
+	return suffix.length > 0 && /^\d+$/.test(suffix);
 }
 
 /**
@@ -54,19 +54,19 @@ export function matchesMailSession(dshSessionId, mailSessionID) {
  * @returns {string|undefined}
  */
 export function pickMailSession(dshSessionIds, mailSessionID) {
-  const base = dshSessionIdForMail(mailSessionID);
-  const list = Array.isArray(dshSessionIds) ? dshSessionIds.map(String) : [];
-  if (list.includes(base)) return base;
+	const base = dshSessionIdForMail(mailSessionID);
+	const list = Array.isArray(dshSessionIds) ? dshSessionIds.map(String) : [];
+	if (list.includes(base)) return base;
 
-  let best;
-  let bestIndex = Infinity;
-  for (const id of list) {
-    if (!matchesMailSession(id, mailSessionID)) continue;
-    const idx = Number(id.slice(base.length + 2));
-    if (idx < bestIndex) {
-      bestIndex = idx;
-      best = id;
-    }
-  }
-  return best;
+	let best;
+	let bestIndex = Infinity;
+	for (const id of list) {
+		if (!matchesMailSession(id, mailSessionID)) continue;
+		const idx = Number(id.slice(base.length + 2));
+		if (idx < bestIndex) {
+			bestIndex = idx;
+			best = id;
+		}
+	}
+	return best;
 }

plugins/dsh-mail-bridge/lib/sse-client.d.ts

@@ -1,17 +1,17 @@
 export interface SseClientOptions {
-    authHeaders: () => Record<string, string>;
-    baseURL: string;
-    path: string;
-    onEvent: (evt: string, data: any) => void;
-    log?: (msg: string) => void;
+	authHeaders: () => Record<string, string>;
+	baseURL: string;
+	path: string;
+	onEvent: (evt: string, data: any) => void;
+	log?: (msg: string) => void;
 }
 export declare function createSSEClient(options: SseClientOptions): {
-    stop: () => void;
-    reset: () => void;
+	stop: () => void;
+	reset: () => void;
 };
 export declare function createFrameParser(): {
-    push: (chunk: string) => Array<{ event: string; data: string; id: string }>;
-    reset: () => void;
-    lastEventId: () => string;
-    setLastEventId: (id: string) => void;
+	push: (chunk: string) => Array<{ event: string; data: string; id: string }>;
+	reset: () => void;
+	lastEventId: () => string;
+	setLastEventId: (id: string) => void;
 };

plugins/dsh-mail-bridge/lib/user-question.d.ts

@@ -2,12 +2,20 @@ export declare function hasOptions(question: any): boolean;
 export declare function optionLabels(question: any): string[];
 export declare function questionTitle(question: any): string;
 export declare function flattenQuestions(questions: any[]): {
-    question: string;
-    options: string[];
-    context: string;
-    multiSelect: boolean;
+	question: string;
+	options: string[];
+	context: string;
+	multiSelect: boolean;
 };
-export declare function answersFromDecision(questions: any[], decision: string, note?: string): {
-    answers: Array<{ id: string; selected: string[]; custom?: string }>;
+export declare function answersFromDecision(
+	questions: any[],
+	decision: string,
+	note?: string,
+): {
+	answers: Array<{ id: string; selected: string[]; custom?: string }>;
 };
-export declare function isBlankAnswer(questions: any[], decision: string, note?: string): boolean;
+export declare function isBlankAnswer(
+	questions: any[],
+	decision: string,
+	note?: string,
+): boolean;