Add Goblin Courier action adventure

[jbeshir]

What changed

• adds Goblin Courier, a compact 5–10 minute top-down action-adventure widget
• makes the courier visibly goblin-like and parcel-bearing, with clearer combat, doors, route markers, and destination cues
• replaces invisible/meta onboarding with a spatial parcel pickup, locked-to-open exit, proximity prompts, and a visible seven-minute delivery clock
• adds a multi-frame directional dash, clearly labelled SHOOT/F controls, focused capture-phase keyboard handling, and compact touch layouts
• separates HUD, objective, prompts, and world markers; adds expressive title treatment and player-facing CC0 asset credits
• preserves the authored routes, enemy roles, upgrades, hazards, instability system, three-phase boss, persistence, reduced motion, and responsive embedding

Why

The first playable version obscured its basic loop and controls: its initial exit was invisible, the player did not read as a goblin courier, keyboard ownership was unreliable, dash feedback was weak, and compact HUD elements overlapped. This overhaul makes the intended run legible and mechanically reliable while keeping its existing depth.

Validation

• node scripts/validate-widgets.mjs — 7 widgets valid
• npm run build:test — pass
• npm run playtest — 34 deterministic Chromium scenarios pass
• npm run build — pass; self-contained single-file production output
• npm run validate:production — offline isolation/smoke pass; SHA-256 637c8c1257bdcda6c147452cedc9463215c4b944bea4c46baaf48bed24212feb
• native first-paint, theme, and 24-cell responsive journey gates — pass

The implementation received independent gameplay and visual review with focused correction passes before the final gates.