fix(hub): agent 会话记忆在配置变更/发版后丢失 + Feishu thread 400 (#19)

Co-authored-by: Hong Jiarong <me@jrhim.com>
Co-committed-by: Hong Jiarong <me@jrhim.com>

hub/src/agent/runner.ts

@@ -198,8 +198,19 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
     if (req.abortController !== undefined) options.abortController = req.abortController;
     if (req.onSdkStderr !== undefined) options.stderr = req.onSdkStderr;
 
+    // When there is no provider session cursor to resume (first run, or after a
+    // role/skill/model config change invalidated claudeSessionId), re-seed the
+    // conversation from this Hub session's prior AgentMessage rows. This keeps
+    // the logical session continuous across config changes and restarts — the
+    // agent still "remembers" the earlier turns even though the SDK starts a
+    // fresh provider session. The resume path above is preferred when available
+    // (it carries tool calls/results natively and avoids re-sending tokens).
+    const promptForAgent = req.resumeSessionId === undefined
+      ? await withSessionHistory(req, req.prompt)
+      : req.prompt;
+
     const conversation = query({
-      prompt: req.prompt,
+      prompt: promptForAgent,
       options,
     });
 
@@ -333,6 +344,39 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
   }
 }
 
+/**
+ * Re-seed a run's prompt with this Hub session's prior conversation when the
+ * SDK cannot resume a provider session (no `resumeSessionId`). Pulls prior
+ * `AgentMessage` rows for this session — excluding the current run's own user
+ * message, which was already persisted before `runAgent` called this — and
+ * frames them as `<session_history>` so the model treats them as prior turns,
+ * not new instructions. The current run's prompt follows as the live request.
+ *
+ * Best-effort: if the history query fails, the run proceeds with the bare
+ * prompt rather than aborting. A cap (`MAX_HISTORY_TURNS`) bounds token cost;
+ * older turns beyond the cap are dropped, preserving the most recent context.
+ */
+async function withSessionHistory(req: RunRequest, prompt: string): Promise<string> {
+  const MAX_HISTORY_TURNS = 40;
+  try {
+    const messages = await req.prisma.agentMessage.findMany({
+      where: { sessionId: req.sessionId, runId: { not: req.runId } },
+      orderBy: { createdAt: "asc" },
+      select: { role: true, content: true },
+      take: MAX_HISTORY_TURNS * 2, // user+assistant per turn
+    });
+    if (messages.length === 0) return prompt;
+    const turns: string[] = [];
+    for (const message of messages) {
+      const label = message.role === "assistant" ? "Assistant" : "User";
+      turns.push(`${label}: ${message.content}`);
+    }
+    return `<session_history>\nThis is the prior conversation in this session, replayed because the provider session could not be resumed. Treat these as earlier turns you produced or received.\n\n${turns.join("\n\n")}\n</session_history>\n\n${prompt}`;
+  } catch {
+    return prompt;
+  }
+}
+
 async function persistAgentMessage(req: RunRequest, role: string, content: string): Promise<void> {
   if (content === "") return;
   try {