feat(02-04): sim/narrative — Lura beat gating (1/4/8 harvest, STRY-10)

- src/sim/narrative/beat-queue.ts: LuraBeatId / LuraBeatProgress contracts
  matching V1Payload.luraBeatProgress + NarrativeSlice; INITIAL frozen.
- src/sim/narrative/lura-gate.ts: LURA_BEAT_THRESHOLDS = {1: arrival,
  4: mid, 8: farewell}; advanceLuraBeatProgress / resolvePendingLuraBeat /
  isLuraBeatPending — pure, no inkjs import, no Date.now (sim-purity rule
  green). The gate counts harvest events, never wall-clock time, so STRY-10
  holds.
- src/sim/narrative/lura-gate.test.ts: 17 cases including the load-bearing
  STRY-10 case (24 hours of FakeClock advance with 0 harvests leaves all
  flags + pending false). Pitfall 10 boundaries pinned at 3/4/5 and 7/8/9.
  pending-set-already + already-visited carry-throughs covered.
- src/sim/garden/commands.ts: harvest() now calls advanceLuraBeatProgress
  AFTER the harvest commit (Pitfall 10 — same-tick boundary). The new
  luraBeatProgress field flows through the returned SimState and into the
  store via the existing Garden.update() path.
- src/sim/garden/commands.test.ts: +5 cases pinning the harvest → beat
  gate edges (1st→arrival, 4th→mid, 8th→farewell, between-threshold
  no-fire, pending preservation when player hasn't visited).
- src/sim/index.ts: re-export ./narrative.

67/67 sim tests green; npm run lint + build exit 0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/sim/garden/commands.test.ts

@@ -352,6 +352,95 @@ describe('compost (GARD-04 / D-07 / no-resource-refund)', () => {
   });
 });
 
+describe('harvest — Lura beat gate integration (Plan 02-04, STRY-10, D-14)', () => {
+  // Helper: hand-roll a state with N prior harvests + a ready rosemary
+  // on tile 0. Used to step into a beat threshold deterministically.
+  function withReadyRosemaryAndPriorHarvests(priorCount: number): SimState {
+    const priorIds = Array.from(
+      { length: priorCount },
+      (_, i) => `season1.soil.dummy-${i + 1}`,
+    );
+    return freshSimState({
+      harvestedFragmentIds: priorIds,
+      garden: {
+        tiles: emptyTiles().map((t, i) =>
+          i === 0
+            ? { idx: 0, plant: { plantTypeId: 'rosemary', plantedAtTick: 0 } }
+            : t,
+        ),
+      },
+    });
+  }
+
+  it('sets luraBeatProgress.pending=arrival after the 1st harvest', () => {
+    const state = withReadyRosemaryAndPriorHarvests(0);
+    const next = harvest(state, 0, 600, fixtureCtx);
+    expect(next.harvestedFragmentIds.length).toBe(1);
+    expect(next.luraBeatProgress.pending).toBe('arrival');
+    expect(next.luraBeatProgress.arrived).toBe(false);
+  });
+
+  it('sets luraBeatProgress.pending=mid after the 4th harvest (arrival already visited)', () => {
+    const base = withReadyRosemaryAndPriorHarvests(3);
+    // Mark arrival already visited so the gate can advance to mid.
+    const state: SimState = {
+      ...base,
+      luraBeatProgress: { ...base.luraBeatProgress, arrived: true },
+    };
+    const next = harvest(state, 0, 600, fixtureCtx);
+    expect(next.harvestedFragmentIds.length).toBe(4);
+    expect(next.luraBeatProgress.pending).toBe('mid');
+    expect(next.luraBeatProgress.arrived).toBe(true); // unchanged
+    expect(next.luraBeatProgress.mid).toBe(false); // pending, not yet visited
+  });
+
+  it('sets luraBeatProgress.pending=farewell after the 8th harvest (arrival + mid visited)', () => {
+    const base = withReadyRosemaryAndPriorHarvests(7);
+    const state: SimState = {
+      ...base,
+      luraBeatProgress: {
+        ...base.luraBeatProgress,
+        arrived: true,
+        mid: true,
+      },
+    };
+    const next = harvest(state, 0, 600, fixtureCtx);
+    expect(next.harvestedFragmentIds.length).toBe(8);
+    expect(next.luraBeatProgress.pending).toBe('farewell');
+  });
+
+  it('does NOT set pending at counts between thresholds (e.g. 5)', () => {
+    const base = withReadyRosemaryAndPriorHarvests(4);
+    const state: SimState = {
+      ...base,
+      luraBeatProgress: {
+        ...base.luraBeatProgress,
+        arrived: true,
+        mid: true, // Already visited; harvest 5 won't trigger
+      },
+    };
+    const next = harvest(state, 0, 600, fixtureCtx);
+    expect(next.harvestedFragmentIds.length).toBe(5);
+    expect(next.luraBeatProgress.pending).toBeNull();
+  });
+
+  it('preserves pending when player has not yet visited the previous beat', () => {
+    // Player harvested 1 (pending=arrival) but never closed the dialogue.
+    // Harvest 2/3/4 should NOT replace pending with mid.
+    const base = withReadyRosemaryAndPriorHarvests(3);
+    const state: SimState = {
+      ...base,
+      luraBeatProgress: {
+        ...base.luraBeatProgress,
+        pending: 'arrival',
+      },
+    };
+    const next = harvest(state, 0, 600, fixtureCtx);
+    expect(next.harvestedFragmentIds.length).toBe(4);
+    expect(next.luraBeatProgress.pending).toBe('arrival');
+  });
+});
+
 describe('simulateOneTick — harvest + compost integration (BLOCKER 3 carry-through)', () => {
   it('routes harvest commands through SimContext and produces a fragment', () => {
     const state = freshSimState({

src/sim/garden/commands.ts

@@ -6,6 +6,7 @@ import type { GrowthStage, PlantInstance, PlantTypeId, Tile } from './types';
 import { GRID_SIZE } from './types';
 import { advanceGrowth } from './growth';
 import { selectFragment } from '../memory/selector';
+import { advanceLuraBeatProgress } from '../narrative/lura-gate';
 
 /**
  * Pure command applications. Each returns a NEW SimState — no mutation.
@@ -144,12 +145,19 @@ export function harvest(
   const harvestedIds = [...state.harvestedFragmentIds, fragment.id];
   // Pitfall 10: check thresholds AFTER the harvest commit.
   const unlockedPlantTypes = computePlantUnlocks(harvestedIds.length);
+  // Plan 02-04: advance Lura beat gate AFTER the commit too. STRY-10
+  // gate gets harvested COUNT (sim-internal), never wall-clock time.
+  const luraBeatProgress = advanceLuraBeatProgress(
+    state.luraBeatProgress,
+    harvestedIds.length,
+  );
 
   return {
     ...state,
     garden: { tiles: nextTiles },
     harvestedFragmentIds: harvestedIds,
     unlockedPlantTypes,
+    luraBeatProgress,
   };
 }