Feat/ranged combat and loadout

[Shaileshukla529]

Summary

The canvas is nearest-upscaled to the wall, capping in-canvas logos at ~95px and leaderboard text at ~12px. Both now render in a DOM layer above the canvas at the display's real resolution.

Changes

• Add scene/dom_overlay.js: canvas-aligned DOM layer; callers still author positions in map space.
• Move decals out of game_logic.js into scene/decals.js as elements; leaderboard text moves to the overlay, panel background stays in canvas. Both hide themselves during the waiting screen.
• Reposition lg/gsoc boxes out of the play area, unlock them, hide helper object layers in Tiled; re-export gsoc_logo.png smaller.
• Remove the temporary viewport diagnostic from the waiting screen.