feat(server): browser module with DB-backed sessions, takeover lease and browser.* capabilities

/browser/providers, /browser/sessions (open/close/list), navigate/snapshot/screenshot/
click/type/scroll/select/extract/download and control acquire/release. Human input
needs an active lease; expiry or captcha moves the session to waiting with a decision;
release forces a fresh snapshot. Downloads are staged under DATA_DIR/tmp, verified by
infohash and submitted through POST /acquisition-plans. Capability count 21 -> 25.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/src/modules/index.ts

@@ -1,6 +1,7 @@
 import { acquisitionOrganizeModule } from "./acquisition-organize/index.ts";
 import { agentModule } from "./agent/index.ts";
 import { authSettingsModule } from "./auth-settings/index.ts";
+import { browserModule } from "./browser/index.ts";
 import { fileManagerModule } from "./file-manager/index.ts";
 import { piModule } from "./pi/index.ts";
 import { schedulesModule } from "./schedules/index.ts";
@@ -24,5 +25,6 @@ export const SERVER_MODULES: readonly ServerModule[] = [
   piModule,
   schedulesModule,
   searchModule,
+  browserModule,
   systemModule,
 ];