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

test/helpers/plan.ts

@@ -1,72 +1,16 @@
-import type { ExecutionPlan, ExecutionPlanNode, PlanEdge, BoundaryNode } from '../../src/generated/common.js';
+import type { PendingEffect } from '../../src/generated/scenarios.js';
 
-/**
- * Small fluent builder for ExecutionPlans, so scenario journeys read like the
- * DAGs they model rather than walls of object literals.
- *
- *   plan('offer_flow')
- *     .node('wait1', 'wait', { duration: 1, unit: 'minutes' })
- *     .node('offer', 'store', { storeSlug: 'starter', offerId: 'pack_1' })
- *     .edge('wait1', 'onComplete', 'offer')
- *     .build();
- *
- * The first node added becomes the start node unless `.start(id)` is called.
- */
-export class PlanBuilder {
-  private readonly nodes: ExecutionPlanNode[] = [];
-  private readonly edges: PlanEdge[] = [];
-  private readonly boundaryNodes: BoundaryNode[] = [];
-  private startNodeId?: string;
-  private runIdValue?: string;
-
-  constructor(
-    private readonly scenarioId: string,
-    private readonly opts: { planId?: string; userId?: string } = {},
-  ) {}
-
-  /** Sets a specific run ID (default: auto-derived from scenarioId). */
-  runId(id: string): this {
-    this.runIdValue = id;
-    return this;
-  }
-
-  node(id: string, type: string, data?: Record<string, unknown>): this {
-    this.nodes.push({ id, type, data: data as ExecutionPlanNode['data'] });
-    if (!this.startNodeId) this.startNodeId = id;
-    return this;
-  }
-
-  edge(source: string, sourceHandle: string, target: string): this {
-    this.edges.push({ id: `e-${source}-${sourceHandle}-${target}`, source, sourceHandle, target });
-    return this;
-  }
-
-  /** Registers a server-side boundary node (handle that calls back to the gateway). */
-  boundary(sourceNodeId: string, sourceHandle: string, nodeId = `b-${sourceNodeId}-${sourceHandle}`): this {
-    this.boundaryNodes.push({ sourceNodeId, sourceHandle, nodeId });
-    return this;
-  }
-
-  start(id: string): this {
-    this.startNodeId = id;
-    return this;
-  }
-
-  build(): ExecutionPlan {
-    return {
-      planId: this.opts.planId ?? `${this.scenarioId}-plan`,
-      scenarioId: this.scenarioId,
-      userId: this.opts.userId ?? 'player-1',
-      startNodeId: this.startNodeId,
-      runId: this.runIdValue ?? `${this.scenarioId}-run`,
-      nodes: this.nodes,
-      edges: this.edges,
-      boundaryNodes: this.boundaryNodes,
-      context: undefined,
-    };
-  }
-}
-
-export function plan(scenarioId: string, opts?: { planId?: string; userId?: string }): PlanBuilder {
-  return new PlanBuilder(scenarioId, opts);
+export function effect(
+  type: string,
+  data: Record<string, unknown> = {},
+  overrides: Partial<PendingEffect> = {},
+): PendingEffect {
+  return {
+    runId: 'run-1',
+    scenarioId: 'scenario-1',
+    nodeId: `${type}-1`,
+    type,
+    data,
+    ...overrides,
+  };
 }