Server-side scenario execution: thin effects client replaces local engine

- engine/ (DagWalker, sessions, IndexedDbPlanStore) deleted; server owns the graph
- trigger/callback/counter carry PendingEffect; GET /sdk/v1/scenarios/pending polled
  (30s jittered heartbeat paused on hidden tab + wait-deadline timers)
- client.effects public API unchanged (done/buy/dismiss/end/claim/battlepass/quest)
- planStateStore removed; loginEvent kept; reconcile() makes server the source of truth
- generated models regenerated; skills/README/CHANGELOG updated

src/generated/api.ts

@@ -9,7 +9,7 @@ import type { PlayerProfile } from './player.js';
 import type { GetProjectStorageResponse, UpdateProjectStorageRequest } from './project-storage.js';
 import type { ClaimQuestRequest, ClaimQuestResponse, ListQuestsResponse, ReportQuestProgressRequest, ReportQuestProgressResponse } from './quests.js';
 import type { ListRemoteConfigsResponse, RemoteConfig } from './remote-config.js';
-import type { GetScenarioRunRequest, GetScenarioRunResponse, HandleScenarioCallbackRequest, HandleScenarioCallbackResponse, TriggerScenarioRequest, TriggerScenarioResponse, UpdateScenarioCounterRequest, UpdateScenarioCounterResponse } from './scenarios.js';
+import type { HandleScenarioCallbackRequest, HandleScenarioCallbackResponse, ListPendingScenarioEffectsResponse, TriggerScenarioRequest, TriggerScenarioResponse, UpdateScenarioCounterRequest, UpdateScenarioCounterResponse } from './scenarios.js';
 import type { GetStorageResponse, UpdateStorageRequest } from './storage.js';
 import type { ListStoresResponse, PurchaseOfferRequest, PurchaseOfferResponse, Store } from './stores.js';
 
@@ -100,12 +100,6 @@ export const api = {
   ): Promise<{ [key: string]: number }> =>
     t.request<{ [key: string]: number }>('GET', '/sdk/v1/sync'),
 
-  getScenarioRun: (
-    t: Transport,
-    body: GetScenarioRunRequest,
-  ): Promise<GetScenarioRunResponse> =>
-    t.request<GetScenarioRunResponse>('POST', '/sdk/v1/scenarios/run', body),
-
   getStorage: (
     t: Transport,
     query?: { types?: string; limit?: number; cursor?: string },
@@ -129,6 +123,11 @@ export const api = {
   ): Promise<ListCatalogItemsResponse> =>
     t.request<ListCatalogItemsResponse>('GET', '/sdk/v1/catalog'),
 
+  listPendingScenarioEffects: (
+    t: Transport,
+  ): Promise<ListPendingScenarioEffectsResponse> =>
+    t.request<ListPendingScenarioEffectsResponse>('GET', '/sdk/v1/scenarios/pending'),
+
   listQuests: (
     t: Transport,
   ): Promise<ListQuestsResponse> =>