feat: add sessions preview rpc and menu prewarm

src/gateway/server-methods/sessions.ts

@@ -6,6 +6,7 @@ import { stopSubagentsForRequester } from "../../auto-reply/reply/abort.js";
 import { clearSessionQueues } from "../../auto-reply/reply/queue.js";
 import { loadConfig } from "../../config/config.js";
 import {
+  loadSessionStore,
   snapshotSessionOrigin,
   resolveMainSessionKey,
   type SessionEntry,
@@ -19,6 +20,7 @@ import {
   validateSessionsDeleteParams,
   validateSessionsListParams,
   validateSessionsPatchParams,
+  validateSessionsPreviewParams,
   validateSessionsResetParams,
   validateSessionsResolveParams,
 } from "../protocol/index.js";
@@ -27,9 +29,12 @@ import {
   listSessionsFromStore,
   loadCombinedSessionStoreForGateway,
   loadSessionEntry,
+  readSessionPreviewItemsFromTranscript,
   resolveGatewaySessionStoreTarget,
   resolveSessionTranscriptCandidates,
   type SessionsPatchResult,
+  type SessionsPreviewEntry,
+  type SessionsPreviewResult,
 } from "../session-utils.js";
 import { applySessionsPatchToStore } from "../sessions-patch.js";
 import { resolveSessionKeyFromResolveParams } from "../sessions-resolve.js";
@@ -59,6 +64,74 @@ export const sessionsHandlers: GatewayRequestHandlers = {
     });
     respond(true, result, undefined);
   },
+  "sessions.preview": ({ params, respond }) => {
+    if (!validateSessionsPreviewParams(params)) {
+      respond(
+        false,
+        undefined,
+        errorShape(
+          ErrorCodes.INVALID_REQUEST,
+          `invalid sessions.preview params: ${formatValidationErrors(
+            validateSessionsPreviewParams.errors,
+          )}`,
+        ),
+      );
+      return;
+    }
+    const p = params as import("../protocol/index.js").SessionsPreviewParams;
+    const keysRaw = Array.isArray(p.keys) ? p.keys : [];
+    const keys = keysRaw
+      .map((key) => String(key ?? "").trim())
+      .filter(Boolean)
+      .slice(0, 64);
+    const limit =
+      typeof p.limit === "number" && Number.isFinite(p.limit) ? Math.max(1, p.limit) : 12;
+    const maxChars =
+      typeof p.maxChars === "number" && Number.isFinite(p.maxChars)
+        ? Math.max(20, p.maxChars)
+        : 240;
+
+    if (keys.length === 0) {
+      respond(true, { ts: Date.now(), previews: [] } satisfies SessionsPreviewResult, undefined);
+      return;
+    }
+
+    const cfg = loadConfig();
+    const storeCache = new Map<string, Record<string, SessionEntry>>();
+    const previews: SessionsPreviewEntry[] = [];
+
+    for (const key of keys) {
+      try {
+        const target = resolveGatewaySessionStoreTarget({ cfg, key });
+        const store = storeCache.get(target.storePath) ?? loadSessionStore(target.storePath);
+        storeCache.set(target.storePath, store);
+        const entry =
+          target.storeKeys.map((candidate) => store[candidate]).find(Boolean) ??
+          store[target.canonicalKey];
+        if (!entry?.sessionId) {
+          previews.push({ key, status: "missing", items: [] });
+          continue;
+        }
+        const items = readSessionPreviewItemsFromTranscript(
+          entry.sessionId,
+          target.storePath,
+          entry.sessionFile,
+          target.agentId,
+          limit,
+          maxChars,
+        );
+        previews.push({
+          key,
+          status: items.length > 0 ? "ok" : "empty",
+          items,
+        });
+      } catch {
+        previews.push({ key, status: "error", items: [] });
+      }
+    }
+
+    respond(true, { ts: Date.now(), previews } satisfies SessionsPreviewResult, undefined);
+  },
   "sessions.resolve": ({ params, respond }) => {
     if (!validateSessionsResolveParams(params)) {
       respond(