feat(hub): session transcript 连续性 + slash commands (/new /resume /reset)

修复每次 @bot 都是失忆状态的问题。
- transcript.ts: JSONL 文件存 session 对话消息(workspace/.cph/sessions/
  <id>.jsonl),append-only;和 Claude Code 一致;ADR-0003 说的'不存全
  历史'是群聊历史,session 对话是 Hub 自己产生的,不冲突
- runner.ts: RunRequest 加 transcriptPath;run 开始时读历史拼进初始
  messages(system prompt 只在首条);run 结束时 append 本轮新消息
  (loadedCount 区分历史 vs 新增,不重复写);best-effort(写失败不丢
  run 结果)
- trigger.ts: slash commands 在 lock 检查之前(/new /resume /reset
  不创建 run 不需要锁);transcriptPath 传给 runner
  /new = 归档当前 session,下次 @bot 自动建新的
  /resume = 恢复最近归档的 session
  /reset = 同 /new
  未知 /cmd 透传给 agent 当普通 prompt
- unit: transcript.test.ts 读写回环/append 累积/损坏行恢复/路径(6)
- integration: trigger.test.ts 加 /new /resume /reset /unknown(4)
修了 slash command 被 lock 挡住的问题(提到 lock 之前)。
vitest run 45/45 通过;tsc rc=0。

hub/src/feishu/trigger.ts

@@ -22,6 +22,7 @@ import type { ModelRegistry } from "../agent/models.js";
 import { runAgent, type ProjectContext } from "../agent/runner.js";
 import { acquireLock, currentLockRunId, releaseLock } from "../lock.js";
 import { canTriggerAgent } from "../permission.js";
+import { transcriptPath } from "../agent/transcript.js";
 
 interface TriggerDeps {
   readonly prisma: PrismaClient;
@@ -69,6 +70,52 @@ export function makeTriggerHandler(deps: TriggerDeps) {
       }
     }
 
+    const prompt = extractPrompt(msg);
+    if (prompt === null) return;
+
+    // Slash commands: session management, not agent runs. These bypass the
+    // lock — they don't create a run, so they can't conflict with one.
+    if (prompt.startsWith("/")) {
+      const cmd = prompt.split(/\s+/)[0];
+      switch (cmd) {
+        case "/new": {
+          await deps.prisma.agentSession.updateMany({
+            where: { projectId, archivedAt: null },
+            data: { archivedAt: new Date() },
+          });
+          await sendText(rt, chatId, "已开新会话,下次 @bot 将从头开始。");
+          return;
+        }
+        case "/resume": {
+          const latest = await deps.prisma.agentSession.findFirst({
+            where: { projectId, archivedAt: { not: null } },
+            orderBy: { archivedAt: "desc" },
+            select: { id: true },
+          });
+          if (latest === null) {
+            await sendText(rt, chatId, "没有可恢复的会话。");
+            return;
+          }
+          await deps.prisma.agentSession.update({
+            where: { id: latest.id },
+            data: { archivedAt: null },
+          });
+          await sendText(rt, chatId, "已恢复上一个会话。");
+          return;
+        }
+        case "/reset": {
+          await deps.prisma.agentSession.updateMany({
+            where: { projectId, archivedAt: null },
+            data: { archivedAt: new Date() },
+          });
+          await sendText(rt, chatId, "已重置,下次 @bot 将从头开始。");
+          return;
+        }
+        default:
+          break;
+      }
+    }
+
     // ADR-0002: if locked by another run, reply busy.
     const existing = await currentLockRunId(deps.prisma, projectId);
     if (existing !== null) {
@@ -76,9 +123,6 @@ export function makeTriggerHandler(deps: TriggerDeps) {
       return;
     }
 
-    const prompt = extractPrompt(msg);
-    if (prompt === null) return;
-
     const project = await deps.prisma.project.findUnique({
       where: { id: projectId },
       select: { workspaceDir: true },
@@ -155,7 +199,7 @@ export function makeTriggerHandler(deps: TriggerDeps) {
     };
 
     // Run the agent — fire-and-forget from the ws handler's perspective.
-    runAgent(deps.provider, deps.tools, { prompt, model, project: projectCtx })
+    runAgent(deps.provider, deps.tools, { prompt, model, project: projectCtx, transcriptPath: transcriptPath(project.workspaceDir, session.id) })
       .then(async (result) => {
         await deps.prisma.agentRun.update({
           where: { id: run.id },