restore extension-api backward compatibility with migration warning

src/extensionAPI.ts

@@ -0,0 +1,32 @@
+// Legacy compat surface for plugins that still import openclaw/extension-api.
+// Keep this file intentionally narrow and forward-only.
+
+const shouldWarnExtensionApiImport =
+  process.env.VITEST !== "true" &&
+  process.env.NODE_ENV !== "test" &&
+  process.env.OPENCLAW_SUPPRESS_EXTENSION_API_WARNING !== "1";
+
+if (shouldWarnExtensionApiImport) {
+  process.emitWarning(
+    "openclaw/extension-api is deprecated. Migrate to api.runtime.agent.* or focused openclaw/plugin-sdk/<subpath> imports. See https://docs.openclaw.ai/plugins/sdk-migration",
+    {
+      code: "OPENCLAW_EXTENSION_API_DEPRECATED",
+      detail:
+        "This compatibility bridge is temporary. Bundled plugins should use the injected plugin runtime instead of importing host-side agent helpers directly. Migration guide: https://docs.openclaw.ai/plugins/sdk-migration",
+    },
+  );
+}
+
+export { resolveAgentDir, resolveAgentWorkspaceDir } from "./agents/agent-scope.js";
+export { DEFAULT_MODEL, DEFAULT_PROVIDER } from "./agents/defaults.js";
+export { resolveAgentIdentity } from "./agents/identity.js";
+export { resolveThinkingDefault } from "./agents/model-selection.js";
+export { runEmbeddedPiAgent } from "./agents/pi-embedded.js";
+export { resolveAgentTimeoutMs } from "./agents/timeout.js";
+export { ensureAgentWorkspace } from "./agents/workspace.js";
+export {
+  resolveStorePath,
+  loadSessionStore,
+  saveSessionStore,
+  resolveSessionFilePath,
+} from "./config/sessions.js";