feat(map-mask): Add Map Mask overlay UI for Infinity Nikki

[caigua1232]

Summary

• Added a transparent, always-on-top Map Mask overlay window.
• Added real game-window client-area tracking with DPI handling and fallback bounds.
• Added Canvas marker rendering, label filters, point details, and debug panels.
• Added local draft point placement, editing, deletion, and JSON export.
• Added smoke-test support and graceful overlay shutdown.

Safety

• Does not access game memory, modify game files, or inject into the game.
• Uses normal Windows window APIs and backend RPC.
• Overlay is click-through by default and can be disabled independently.

Testing

• corepack pnpm run compile:app
• corepack pnpm run typecheck
• git diff --cached --check

Known Limitations

• Marker accuracy depends on stable screenshot capture and maximum big-map zoom.
• Real-window tracking is Windows-first.
• Debug/calibration controls are intentionally developer-oriented.

Files Changed Overview

• Main-process overlay and window tracker
• Preload API and renderer types
• Map Mask routes, screen, Canvas renderer, and launcher button
• Smoke-test service

Manual Verification Needed

• Verify overlay tracking, click-through behavior, marker popup, and application exit.