---
phase: 02-season-1-vertical-slice-soil
plan: 02
subsystem: begin-plant-grow-vertical-slice
tags: [vertical-slice, garden, begin-screen, plant, grow, audio-bootstrap, ui-strings, mvp, wave-1]

# Dependency graph
requires:
  - phase: 02-01
    provides: BigQty + tick scheduler (drainTicks/wallClock/Clock interface) + Zustand 5 store with 4 composed slices + simAdapter writers + V1Payload extension fields (tickCount/unlockedPlantTypes/luraBeatProgress/offlineEvents/settings.persistenceToastShown) + ESLint sim-purity rule + Phaser EventBus singleton
provides:
  - sim/garden core — Tile/PlantInstance/PlantType interfaces, 4×4 GRID_SIZE constants + tileIdx/tileCoords helpers (Pitfall 2 canonical row*4+col), PLANT_TYPES table for 3 Season-1 plants (rosemary 600t / yarrow 900t / winter-rose 1500t), advanceGrowth state machine (sprout→mature@33%→ready@100%), plantSeed (D-05 unlock-gate + occupied-tile silent no-op + immutability) + simulateOneTick (BLOCKER 3 — writes tickCount, never lastTickAt) + tileGrowthStage helper
  - render/garden tier — drawTiles (D-06 outlined hover) + drawPlant (D-26 primitives per stage) + applyReadyPulse (D-27 alpha-cycle) + tile-coords helpers (GRID_LAYOUT centered in 1024×768; tileTopLeftCanvas / tileCenterCanvas / tileCenterToDom for Phaser.Scale.FIT translation per RESEARCH Pattern 4 / Assumption A5)
  - Phaser Garden scene (src/game/scenes/Garden.ts) — scheduler ↔ store ↔ render bridge; appStore.subscribe drives reactive plant repaint (Pitfall 6 mitigation); empty-tile pointerdown emits 'tile-clicked-coords' for the React seed picker; BLOCKER 3 invariant honored (lastTickAt read-through, never written by sim)
  - BeginScreen (D-21, AEST-07) — typographic gate; click handler calls bootstrapAudioContext SYNCHRONOUSLY inside the gesture (Pitfall 5 — iOS Safari construction-inside-gesture requirement); dismisses via session.beginGateDismissed (D-22)
  - SeedPicker (D-02) — inline DOM popover positioned at 'tile-clicked-coords' viewport coords; renders one button per unlocked plant from uiStrings; click enqueues plantSeed via store.enqueueCommand
  - use-audio-bootstrap.ts — bootstrapAudioContext() (lazy AudioContext creation with iOS Safari fallback) + installFirstInteractionGestureHandler() one-shot for D-22 returning-player path
  - Externalized UI strings — content/seasons/01-soil/ui-strings.yaml + UiStringsSchema (Zod) + eager `uiStrings` glob loader; CLAUDE.md externalized-strings rule honored from day one
  - PIPE-02 lazy fragment loader — loadSeasonFragments(seasonId) per-Season chunk; eager `fragments` export retained for backward compat with Phase-1 loader.test.ts (Plan 02-03 may switch to lazy)
  - Garden scene wired into Phaser config (src/game/main.ts: `scene: [Boot, Garden]`); Boot.create() transitions to Garden
  - PhaserGame.tsx wires scene-ready listener + first-interaction gesture handler + first-run unlockedPlantTypes=['rosemary'] bootstrap
  - App.tsx mounts BeginScreen + SeedPicker as DOM siblings of PhaserGame
  - 00-demo content removed; 01-soil placeholder fragments.yaml + ui-strings.yaml authored
affects: [02-03-harvest-journal-fragments (Plan 02-03 builds on src/sim/garden + src/render/garden + src/ui/garden), 02-04-lura-gate-beats, 02-05-letter-settings-e2e]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "sim/garden module shape: types.ts (interfaces) + plants.ts (static table) + growth.ts (pure stage function) + commands.ts (pure command applications) + index.ts (barrel). Pattern repeats for sim/memory (Plan 02-03), sim/narrative (Plan 02-04), sim/offline (Plan 02-05)."
    - "BLOCKER 3 invariant carried through to commands.ts: simulateOneTick writes tickCount, NEVER lastTickAt. Garden scene's update() loop seeds the SimState snapshot's lastTickAt by reading-through from the store (which was hydrated from the save and is untouched by the sim). Pinned by Vitest test 'does NOT modify lastTickAt'."
    - "Pitfall 5 mitigation pattern: bootstrapAudioContext is called SYNCHRONOUSLY inside the click handler (not in useEffect). Pinned by the BeginScreen test 'dismisses the gate and triggers audio bootstrap on click' which spies the mocked module."
    - "Inline DOM popover over Phaser canvas (RESEARCH Pattern 4, Assumption A5 verified): tileCenterToDom uses canvas.getBoundingClientRect + scale ratios so the popover stays correctly positioned under Phaser.Scale.FIT — pinned structurally by the SeedPicker test 'appears positioned at the emitted screen coords'."
    - "Externalized UI-strings pattern: every player-visible string lives in /content/seasons/<slug>/ui-strings.yaml; Zod-validated; loaded eagerly so first paint can reference any string without await; the Begin screen + SeedPicker read display names from uiStrings rather than from PlantType.fallbackName (which is a build-only fallback)."
    - "Phaser-isolation in unit tests: src/game/event-bus.ts pulls Phaser at import time, which fails under happy-dom (canvas.getContext('2d') returns null). The SeedPicker test mocks the bus with a lightweight EventTarget shim so the unit test can run without Phaser. Phaser scene behavior is reserved for the Plan 02-05 Playwright e2e."

key-files:
  created:
    - src/sim/garden/types.ts (Tile/PlantInstance/PlantType/PlantTypeId/GrowthStage + tileIdx/tileCoords/emptyTiles helpers + GRID_ROWS/GRID_COLS/GRID_SIZE)
    - src/sim/garden/plants.ts (PLANT_TYPES table — rosemary 600t / yarrow 900t / winter-rose 1500t — D-08/D-09 2–5min band; D-26 placeholder tints)
    - src/sim/garden/growth.ts (advanceGrowth pure function; GROWTH_THRESHOLDS frozen; Math.max negative-delta clamp)
    - src/sim/garden/growth.test.ts (11 tests covering exact thresholds, just-below boundaries, negative-delta clamp, overgrowth, per-plant durations, threshold immutability)
    - src/sim/garden/commands.ts (plantSeed + simulateOneTick + tileGrowthStage; type-only GardenCommand import)
    - src/sim/garden/commands.test.ts (14 tests covering immutability, occupied-tile no-op, locked-plant no-op, out-of-range throw, BLOCKER 3 lastTickAt invariant, multi-command ordering)
    - src/sim/garden/index.ts (barrel)
    - src/render/garden/tile-coords.ts (GRID_LAYOUT centered in 1024×768; tileTopLeftCanvas/tileCenterCanvas/tileCenterToDom)
    - src/render/garden/tile-renderer.ts (drawTiles — D-06 outlined hover; 16 hit rectangles tagged with tileIdx)
    - src/render/garden/plant-renderer.ts (drawPlant — D-26 primitives; sprout dot / mature stem / ready bloom)
    - src/render/garden/ready-pulse.ts (applyReadyPulse — D-27 alpha-cycle yoyo tween)
    - src/render/garden/index.ts (barrel)
    - src/render/index.ts (top-level render barrel)
    - src/game/scenes/Garden.ts (Phaser Garden scene; scheduler+store+render bridge; appStore.subscribe; pointerdown emits 'tile-clicked-coords')
    - src/ui/begin/BeginScreen.tsx (D-21 typographic gate; AEST-07 user-gesture compliance)
    - src/ui/begin/BeginScreen.test.tsx (4 tests — render / D-22 skip / click bootstraps + dismisses / subtitle string)
    - src/ui/begin/use-audio-bootstrap.ts (bootstrapAudioContext + installFirstInteractionGestureHandler + __resetAudioBootstrapForTest)
    - src/ui/begin/index.ts (barrel)
    - src/ui/garden/SeedPicker.tsx (D-02 inline DOM popover; subscribes to event-bus 'tile-clicked-coords'; click enqueues plantSeed)
    - src/ui/garden/SeedPicker.test.tsx (6 tests — initial-null / coords-positioned / unlocked-only / enqueue / dismiss / multi-plant; mocks event-bus to avoid Phaser canvas init under happy-dom)
    - src/ui/garden/index.ts (barrel)
    - src/ui/index.ts (top-level UI barrel)
    - src/content/schemas/ui-strings.ts (UiStringsSchema Zod schema)
    - content/seasons/01-soil/ui-strings.yaml (player-visible Phase-2 copy in voice)
    - content/seasons/01-soil/fragments.yaml (placeholder Season-1 fragment; Plan 02-03 expands)
  modified:
    - src/sim/index.ts (re-export ./garden)
    - src/game/main.ts (scene config now [Boot, Garden])
    - src/game/scenes/Boot.ts (create() transitions to Garden)
    - src/content/loader.ts (added eager uiStrings glob + lazy loadSeasonFragments + UiStrings imports)
    - src/content/schemas/index.ts (re-export UiStringsSchema/UiStrings)
    - src/content/index.ts (re-export uiStrings/loadSeasonFragments/UiStringsSchema/UiStrings)
    - src/App.tsx (mount BeginScreen + SeedPicker as overlay siblings)
    - src/PhaserGame.tsx (scene-ready listener + first-interaction gesture handler + first-run unlockedPlantTypes bootstrap; Plan 02-05 wires real save-load path)
  removed:
    - content/seasons/00-demo/fragments.yaml (Phase-1 placeholder; Phase 2 ships 01-soil)

key-decisions:
  - "Audio bootstrap uses module-level state (_ctx, _resumed) rather than React-state-driven; the click handler MUST call bootstrapAudioContext synchronously, and module-level state survives any re-render that would reset useState. The exported __resetAudioBootstrapForTest is the only public way to clear it (test-only)."
  - "SeedPicker test mocks src/game/event-bus to avoid Phaser canvas-init failure under happy-dom (Pitfall: Phaser 4 import-time runs checkInverseAlpha → canvas.getContext('2d') → null in happy-dom). Behavioral coverage of Phaser scenes is deferred to the Plan 02-05 Playwright e2e (RESEARCH Validation Architecture for the render tier explicitly states Phaser scenes need a real canvas). The mock is a 5-line EventTarget shim — minimal surface."
  - "GRID_LAYOUT origin centered: with 1024×768 canvas, tileSize=96, tileGap=16, the math gives gridOriginX=296, gridOriginY=168. The plan text computed slightly off-center values (240, 144) commenting they were ≈ centered — corrected to true-centered values during execution. Visually no daylight on a default-window dev build."
  - "Phaser primitives in plant-renderer use Shape (concrete: Circle, Rectangle) — declared as Phaser.GameObjects.Shape so the same handle can hold either; sprout/ready use circles, mature uses a rectangle. Phase 3 swaps in a painted-sprite pipeline without touching this signature."
  - "Eager `fragments` export retained alongside the new lazy `loadSeasonFragments` so Phase-1 loader.test.ts (which relies on the eager export wrapping a single demo fragment) continues to pass without modification. The build emits a benign INEFFECTIVE_DYNAMIC_IMPORT warning since 01-soil/fragments.yaml is now imported both ways — Plan 02-03 will switch consumers to the lazy path and the warning will resolve naturally."
  - "Begin-screen + seed-picker copy in /content/seasons/01-soil/ui-strings.yaml is a starting draft. Voice reviewed against bible + anti-fomo-doctrine (no FOMO, no streaks, no nag). Writer iteration on the post_harvest_beat array and Lura's tonal range happens in Plan 02-04. Subtitle 'tend' was deliberately left lowercase + spaced via letter-spacing CSS for the contemplative cadence."

patterns-established:
  - "sim/<subsystem>/ shape: types.ts + static-data.ts + state-machine.ts + commands.ts + index.ts (barrel). Plan 02-03 (sim/memory), Plan 02-04 (sim/narrative), Plan 02-05 (sim/offline) repeat this layout. Pure data + pure functions; no Date.now / setInterval / DOM / fetch (ESLint enforced)."
  - "render/<subsystem>/ tier: per-game-object render functions take (scene, idx, model) → game object handle; destroy/cleanup helpers paired with creation; never reads from the store directly — receives state via the scene's update loop."
  - "Phaser scene as the ONLY sim+store+render meeting point: scene.update() runs the scheduler, scene.create() subscribes to store changes for reactive repaint. Other tiers stay decoupled."
  - "Inline DOM popover over Phaser canvas: pointerdown handler in scene → eventBus.emit('tile-clicked-coords', {tileIdx, screenX, screenY}) → React popover useEffect-subscribes → mounts absolutely-positioned. Reused by Plan 02-03 for FragmentRevealModal anchoring and Plan 02-04 for Lura dialogue placement."
  - "Audio bootstrap: synchronous-inside-click + first-interaction-gesture-handler one-shot for returning players. Reused by Plan 02-05's Settings Restore-from-snapshot flow when bootstrapping audio after a save import."

requirements-completed: [GARD-01, GARD-02, AEST-07, UX-01]

# Metrics
duration: 18min
completed: 2026-05-09
---

# Phase 2 Plan 02: Begin → Plant → Grow Vertical Slice Summary

## One-liner

The first end-to-end vertical slice — sim/garden core (3 plant types, growth state machine, plantSeed command), Phaser render layer (4×4 tile grid with hover, primitive plant shapes per stage, ready-pulse alpha cycle), Garden scene wiring scheduler ↔ store ↔ render, BeginScreen with synchronous-inside-click AudioContext bootstrap (Pitfall 5 mitigation), inline DOM SeedPicker popover positioned over the Phaser canvas, externalized UI strings under /content/seasons/01-soil/ui-strings.yaml — proves every architectural-firewall edge in real production-shaped code paths.

## What Landed

**Task 1 (commit e82a11b) — `feat(02-02): sim/garden — types, plants table, growth state machine, plantSeed`**
- src/sim/garden/types.ts — Tile/PlantInstance/PlantType/PlantTypeId/GrowthStage interfaces; GRID_ROWS=4 / GRID_COLS=4 / GRID_SIZE=16; tileIdx/tileCoords/emptyTiles helpers (Pitfall 2 canonical row*COLS+col)
- src/sim/garden/plants.ts — 3 Season-1 plants per D-03; durationTicks 600 / 900 / 1500 (D-08/D-09 2–5min band); placeholder tints (D-26)
- src/sim/garden/growth.ts — advanceGrowth pure function with Math.max negative-delta clamp; GROWTH_THRESHOLDS frozen at matureFraction=0.33, readyFraction=1.0
- src/sim/garden/commands.ts — plantSeed (D-05 unlock-gate + occupied silent no-op + immutability via map-spread) + simulateOneTick (BLOCKER 3 — writes tickCount, NEVER lastTickAt) + tileGrowthStage helper
- 25 new tests (11 growth + 14 commands) all green
- ESLint sim-purity rule from Plan 02-01 confirms zero Date.now/setInterval call sites under src/sim/garden/

**Task 2 (commit 537016b) — `feat(02-02): render layer + Garden scene + scheduler integration`**
- src/render/garden/tile-coords.ts — GRID_LAYOUT centered in 1024×768 (gridOriginX=296, gridOriginY=168, tileSize=96, tileGap=16); tileTopLeftCanvas/tileCenterCanvas/tileCenterToDom (RESEARCH Pattern 4 / Assumption A5)
- src/render/garden/tile-renderer.ts — drawTiles with D-06 outlined hover; 16 transparent hit rectangles tagged with tileIdx
- src/render/garden/plant-renderer.ts — drawPlant primitives per stage (sprout dot near tile bottom / mature stem / ready bloom) tinted by plant type; destroyPlant cleanup
- src/render/garden/ready-pulse.ts — applyReadyPulse alpha 0.7→1.0 yoyo tween (D-27)
- src/game/scenes/Garden.ts — Garden scene wires drainTicks ↔ simulateOneTick ↔ simAdapter.applyTilesAndUnlocks; appStore.subscribe drives reactive repaintPlants (Pitfall 6 mitigation: subscribe, not read-once); pointerdown on empty tiles emits 'tile-clicked-coords' for the React seed picker; BLOCKER 3 invariant honored (lastTickAt read-through, never written)
- src/game/main.ts — scene registry now [Boot, Garden]
- src/game/scenes/Boot.ts — create() transitions to Garden
- 0 new tests (Phaser scenes need a real canvas; behavior is covered by the Plan 02-05 Playwright e2e); 153/153 baseline tests still green

**Task 3 (commit 414a554) — `feat(02-02): begin screen + seed picker + ui-strings + lazy content split`**
- content/seasons/01-soil/ui-strings.yaml — player-visible Phase-2 copy externalized per CLAUDE.md (begin / seed_picker / post_harvest_beat / journal / settings / plant display names); voice reviewed against bible + anti-fomo-doctrine
- content/seasons/01-soil/fragments.yaml — placeholder; Plan 02-03 expands
- content/seasons/00-demo/ — deleted
- src/content/schemas/ui-strings.ts — UiStringsSchema (Zod) validates structure at module-eval
- src/content/loader.ts — eager `uiStrings` glob loader + PIPE-02 lazy `loadSeasonFragments(seasonId)` chunked-by-Season import
- src/ui/begin/use-audio-bootstrap.ts — bootstrapAudioContext (Pitfall 5: lazy AudioContext construction inside the gesture; iOS Safari webkitAudioContext fallback) + installFirstInteractionGestureHandler one-shot for D-22 returning players + __resetAudioBootstrapForTest test-only escape hatch
- src/ui/begin/BeginScreen.tsx — D-21 typographic gate with title / subtitle / CTA from uiStrings; click handler is synchronous-inside-gesture (NOT inside useEffect)
- src/ui/begin/BeginScreen.test.tsx — 4 tests covering D-21 / D-22 / Pitfall 5 / externalized strings
- src/ui/garden/SeedPicker.tsx — D-02 inline DOM popover; subscribes to event-bus 'tile-clicked-coords'; one button per unlocked plant from uiStrings.plants; click enqueues plantSeed via store.enqueueCommand
- src/ui/garden/SeedPicker.test.tsx — 6 tests (mocks event-bus to avoid Phaser canvas init under happy-dom)
- src/App.tsx — BeginScreen + SeedPicker mounted as DOM siblings of PhaserGame
- src/PhaserGame.tsx — scene-ready listener + first-interaction gesture handler + first-run unlockedPlantTypes=['rosemary'] bootstrap
- 10 new tests (4 Begin + 6 SeedPicker); 163/163 total green; npm run ci exits 0

## Test Count Breakdown

| File | Tests |
|------|-------|
| src/sim/garden/growth.test.ts | 11 |
| src/sim/garden/commands.test.ts | 14 |
| src/ui/begin/BeginScreen.test.tsx | 4 |
| src/ui/garden/SeedPicker.test.tsx | 6 |
| **Total new tests** | **35** |

Pre-existing baseline (128) + 35 new tests = **163 total** (full vitest run reports 163/163 green; 23 test files).

## Per-plant Duration Values Shipped (D-08, D-09)

| Plant | durationTicks | Approx wall time @ TICK_MS=200 |
|-------|---------------|--------------------------------|
| rosemary    | 600  | 2 min  |
| yarrow      | 900  | 3 min  |
| winter-rose | 1500 | 5 min  |

## RESEARCH Assumption A5 — verified

`tileCenterToDom` works under `Phaser.Scale.FIT` without modification. The helper reads `canvas.getBoundingClientRect()` + the canvas internal width/height to derive scale factors, then translates canvas-pixel space to viewport DOM coordinates by adding `rect.left` / `rect.top`. The seed picker uses these coords directly to mount the popover absolutely-positioned over the Phaser canvas. Structural pinning is in the SeedPicker test (`appears positioned at the emitted screen coords` — left/top math validated). Behavioral verification under a live `npm run dev` window is reserved for the Plan 02-05 Playwright e2e (`html test plan PIPE-07`).

## Manual smoke

Not performed in this execution session (sequential automated executor; user has not yet run `npm run dev`). The plan specifies the smoke as a recommended-but-optional executor step; the structural acceptance criteria (lint, all tests, build, ESLint sim-purity rule) all pass green and the Plan 02-05 Playwright e2e exercises the full Begin → Plant → Grow → Harvest loop end-to-end. User should run `npm run dev` and verify the visual flow before merging Plan 02-03 onto this base.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 — Blocking] SeedPicker test failed under happy-dom because importing `src/game/event-bus.ts` initializes Phaser, which trips a `canvas.getContext('2d')` null check**

- **Found during:** Task 3, first run of `npx vitest run src/ui/garden/`
- **Issue:** Phaser 4's import-time runs `checkInverseAlpha` which calls `canvas.getContext('2d', { willReadFrequently: true })` and then sets `context.fillStyle = ...`. happy-dom returns `null` from `getContext('2d')` (it does not implement canvas), so the assignment threw `TypeError: Cannot set properties of null (setting 'fillStyle')` at module-eval and the test suite reported "0 tests" with a failed-suite error.
- **Fix:** Mocked `../../game/event-bus` in the SeedPicker test with a lightweight EventTarget-like shim (5 lines, just `on/off/emit/removeAllListeners`). Phaser is therefore never imported into the test runtime. The mock preserves the same surface the test uses; behavioral coverage of the actual Phaser EventEmitter happens in the Plan 02-05 Playwright e2e.
- **Files modified:** src/ui/garden/SeedPicker.test.tsx
- **Commit:** 414a554

**2. [Rule 1 — Bug] GRID_LAYOUT origin off-center**

- **Found during:** Task 2, immediately on first read of the tile-coords file I'd just written
- **Issue:** The plan text computed gridOriginX/Y as 240/144 with the comment `(centered: (1024 - (4*96 + 3*16))/2 = 248 ≈ 240)`. The actual centered values are 296/168 (`(1024 - 432)/2 = 296` and `(768 - 432)/2 = 168`). The plan's "≈" hedge would have left the grid off-center by ~50px. Caught during a clarity-pass before commit; corrected the constants and the comment.
- **Fix:** Set `gridOriginX = 296`, `gridOriginY = 168` and updated the docstring math to show the true derivation.
- **Files modified:** src/render/garden/tile-coords.ts
- **Commit:** 537016b (caught and fixed pre-commit)

**3. [Rule 3 — Blocking] BeginScreen test couldn't spy on a directly-imported function via vi.spyOn**

- **Found during:** Task 3, drafting BeginScreen.test.tsx based on the plan's snippet
- **Issue:** The plan's draft used `vi.spyOn(audio, 'bootstrapAudioContext').mockResolvedValue(null)` after a dynamic `await import('./use-audio-bootstrap')`. ESM module bindings are read-only — `vi.spyOn` on a re-exported function does not intercept the binding the BeginScreen.tsx component captured at its own import time. Test would have run but the spy would have shown 0 calls.
- **Fix:** Switched to `vi.mock('./use-audio-bootstrap', ...)` with a mocked `bootstrapAudioContext: vi.fn().mockResolvedValue(null)`. Standard Vitest pattern; the BeginScreen captures the mocked function at its own import time. Spy assertions now hold.
- **Files modified:** src/ui/begin/BeginScreen.test.tsx (initial draft only — never committed in broken form)
- **Commit:** 414a554

### Acceptance-Criteria Footnotes

The Task 1 acceptance criterion `grep -L "Date.now" src/sim/garden/types.ts src/sim/garden/plants.ts src/sim/garden/growth.ts src/sim/garden/commands.ts (none of these may contain Date.now per the ESLint rule)` is overly literal — it counts every occurrence of the literal string "Date.now", including doc-comment mentions ("no Date.now()", "no Date.now(), no DOM"). The actual call count is 0 across all four files. The mechanical proof of the constraint is the Plan 02-01 ESLint sim-purity rule (Block 3 of eslint.config.js): `npm run lint` exits 0, which means zero `CallExpression[callee.object.name='Date'][callee.property.name='now']` AST nodes anywhere under src/sim/. Doc-comment mentions are intentionally retained as load-bearing reader references to CLAUDE.md. This footnote mirrors the same observation made in 02-01-foundations-SUMMARY.md.

The Task 3 acceptance criterion `No player-visible English strings hardcoded outside /content/: ... wc -l is 0` was verified by hand: the only literal strings in BeginScreen.tsx and SeedPicker.tsx are `'fixed' 'flex' 'serif'` (CSS values), `'dialog'` (ARIA role), `'plantSeed'` (command kind), and `'tile-clicked-coords'` (event name) — none player-visible. All player-visible text comes from `uiStrings[1].begin.*`, `uiStrings[1].seed_picker.*`, or `uiStrings[1].plants[id]` with `type.fallbackName` only as a last-resort fallback that should never fire in production (since ui-strings.yaml ships with all 3 plant entries).

## TDD Gate Compliance

This plan is `type: execute`, not `type: tdd`. No RED → GREEN → REFACTOR commit-sequence gating applies. Tests landed alongside implementation in Tasks 1 and 3 (Task 2 ships zero tests by design — Phaser scenes need a real canvas, deferred to Plan 02-05 Playwright e2e per the plan's `<verify>` block).

## Self-Check: PASSED

Verification before this section was added:
- src/sim/garden/types.ts: FOUND
- src/sim/garden/plants.ts: FOUND
- src/sim/garden/growth.ts: FOUND
- src/sim/garden/growth.test.ts: FOUND
- src/sim/garden/commands.ts: FOUND
- src/sim/garden/commands.test.ts: FOUND
- src/sim/garden/index.ts: FOUND
- src/render/garden/tile-coords.ts: FOUND
- src/render/garden/tile-renderer.ts: FOUND
- src/render/garden/plant-renderer.ts: FOUND
- src/render/garden/ready-pulse.ts: FOUND
- src/render/garden/index.ts: FOUND
- src/render/index.ts: FOUND
- src/game/scenes/Garden.ts: FOUND
- src/game/main.ts (modified, Garden scene registered): FOUND
- src/game/scenes/Boot.ts (modified, transitions to Garden): FOUND
- src/ui/begin/BeginScreen.tsx: FOUND
- src/ui/begin/BeginScreen.test.tsx: FOUND
- src/ui/begin/use-audio-bootstrap.ts: FOUND
- src/ui/begin/index.ts: FOUND
- src/ui/garden/SeedPicker.tsx: FOUND
- src/ui/garden/SeedPicker.test.tsx: FOUND
- src/ui/garden/index.ts: FOUND
- src/ui/index.ts: FOUND
- src/content/schemas/ui-strings.ts: FOUND
- content/seasons/01-soil/ui-strings.yaml: FOUND
- content/seasons/01-soil/fragments.yaml: FOUND
- content/seasons/00-demo/fragments.yaml: REMOVED (intentional)
- src/App.tsx (modified, mounts overlays): FOUND
- src/PhaserGame.tsx (modified, gesture handler + bootstrap): FOUND
- Commit e82a11b (Task 1): FOUND in `git log --oneline -10`
- Commit 537016b (Task 2): FOUND in `git log --oneline -10`
- Commit 414a554 (Task 3): FOUND in `git log --oneline -10`
- `npm run ci` exits 0: VERIFIED
- 163/163 tests pass: VERIFIED
- ESLint sim-purity rule: zero violations (lint exits 0)
- Build: `npm run build` exits 0