docs: Phase 6 design spec (icon + l10n finalize + juice + store assets)

App icon = clean 2x2 glossy block mark (vector, no AI image). l10n EN/KO
finalize + KO overflow pass. Light juice: sound/haptics toggle, themed
settings, button press feedback, screen transitions. Store feature graphic +
EN/KO screenshots. Procedural visuals mean no raster background assets needed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/superpowers/specs/2026-06-13-phase6-design.md

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+# Phase 6 — Localization Finalize + Icon + Juice + Store Assets (Design)
+
+**Date:** 2026-06-13
+**Status:** Approved (owner approved design 2026-06-13)
+
+## Context
+
+Phases 0–5 are complete (gameplay, seasons, endless, commercial polish, remote
+content, Firebase analytics, AdMob + IAP). Phase 6 is the pre-release polish
+round. The master plan assumed AI-generated background/tilesheet **images**, but
+Phase 3.5 implemented all in-game visuals **procedurally** (CustomPainter glossy
+tiles, painted season backgrounds). So image assets are NOT needed for gameplay;
+the only image deliverables are the **app icon** and **store graphics**, both of
+which are produced as vectors in the game's existing visual language — no
+external AI image generation required.
+
+Owner is a non-developer; Claude produces all code and all vector art.
+
+## Visual identity (established, reused here)
+
+- Deep navy background gradient `#101736 → #192555 → #2C3168` (season-1 palette).
+- Glossy rounded blocks in four brand colors: pink `#FF7EB3`, yellow `#FFD166`,
+  cyan `#6FCDF5`, green `#7EDB9C` (each rendered light→base→dark vertical
+  gradient + a soft white highlight ellipse near the top — same look as the
+  in-game `paintGlossyTile`).
+
+## Workstreams
+
+### 1. App icon (DECIDED: "Clean 2×2 block mark")
+
+- Composition: rounded-square, deep-navy background, a centered 2×2 grid of the
+  four glossy brand-color blocks (pink top-left, yellow top-right, cyan
+  bottom-left, green bottom-right). No cherry-blossom accent (icon must be a
+  permanent, season-independent brand asset). Mirrors the existing in-app
+  `_logoMark`.
+- Blocks kept within the central safe zone so Android's circular/rounded mask
+  never clips them.
+- Deliverables:
+  - A master **SVG** committed to the repo (source of truth).
+  - A **1024×1024 PNG**, opaque (no alpha) for the iOS App Store.
+  - **Android adaptive icon**: foreground = the 2×2 blocks (transparent
+    surround), background = the navy gradient (flat or gradient drawable).
+  - All platform sizes generated via the `flutter_launcher_icons` package
+    (config in `pubspec.yaml` / `flutter_launcher_icons.yaml`), replacing the
+    default Flutter icon on both platforms.
+- Tooling: rasterize SVG→PNG with a deterministic, scriptable converter
+  (`rsvg-convert`, or a tiny Dart/`image` script, or `flutter_svg` render). The
+  conversion command is checked in so the icon can be regenerated.
+
+### 2. Localization finalize (EN + KO)
+
+- Audit every user-facing screen for hardcoded (non-l10n) strings; move any to
+  ARB. Screens to sweep: splash, season title, home, season map, game (HUD +
+  result overlays), settings, tutorial, snackbars.
+- Verify EN copy is store-quality and KO copy reads natively (no machine-y
+  phrasing).
+- **KO integrity pass:** run the app under the `ko` locale on the simulator and
+  confirm no text overflow/truncation/clipping on any screen (Korean strings are
+  often longer/shorter than English — buttons, chips, result cards, settings
+  rows). Fix overflows (wrap, ellipsis, sizing) where found.
+- Add any new keys introduced by workstream 3 (sound/haptics toggle labels).
+
+### 3. Juice / polish pass (light, on top of Phase 3.5; BGM stays on hold)
+
+- **Sound on/off setting** (real gap — commercial games need it): a single
+  toggle in Settings that enables/disables SFX, persisted in `SaveRepository`
+  (additive flag, saveVersion stays 1) and applied through `AudioService`. The
+  same flag also gates gameplay haptics (no separate haptics toggle — one
+  "Sound & vibration" control keeps Settings simple).
+- **Settings screen theming:** the just-added Settings screen is a plain
+  `ListView`; give it the game's look (transparent scaffold over
+  `SeasonBackground`, themed text/cards) so it matches the rest of the app.
+- **Button press feedback:** subtle scale-on-press for the primary buttons
+  (home Adventure/Classic, map nodes) for a more tactile "game" feel.
+- **Screen transitions:** a gentle shared fade(-through) transition for
+  home → map → game navigation instead of the default platform slide.
+
+### 4. Store assets
+
+- **Feature graphic (Play, 1024×500):** navy + glossy blocks + "Block Seasons"
+  wordmark + a short tagline, in the icon's visual language. Produced as vector
+  → PNG and committed under `docs/store/`.
+- **Screenshots:** captured from the running app on the simulator — home,
+  season map, gameplay (mid-combo), stage win (stars), endless game-over — in
+  **both EN and KO**. Stored under `docs/store/screenshots/<locale>/`.
+- Exact per-store framing/sizes (iOS 6.7"/6.5", Play phone) are finalized at
+  submission time in **Phase 7**; Phase 6 captures the raw, clean source shots.
+
+## Out of scope (explicit)
+
+- BGM / music (on hold by prior decision).
+- AI-generated raster backgrounds/tilesheets (visuals are procedural).
+- Real AdMob unit IDs and store IAP product creation (owner prerequisites,
+  tracked for the Phase 5 finalize step between Phase 6 and Phase 7).
+- Final per-store screenshot framing (Phase 7).
+
+## Success criteria
+
+- Real app icon shows on both iOS and Android (no default Flutter icon).
+- KO full play-through has zero text overflow/clipping; no hardcoded strings.
+- Sound toggle works and persists across relaunch.
+- Feature graphic + EN/KO screenshot set committed under `docs/store/`.
+- `flutter analyze` clean; full test suite green (≥169, plus any new tests for
+  the sound-setting persistence).