Title screen rewrite, walking-scene parallax, global DEBUG menu

TitleScreen is rewritten — poster background, gold-gradient title with an ink stroke, the PLAY button restyled to match the bottom menu (grey + speed lines + selected sheen), and six color-tinted sparkle squares positioned at character hand locations. The dev-only shortcut buttons that used to crowd the title screen are gone from there.

The walking-battle scene gains a `biome` field that resolves to four stacked layers (sky / back / mid / fore) rendered behind the scene; back and mid tile as parallax while sky and fore stay viewport-locked. Enemy triggers now render as creature sprites instead of colored placeholders, so the new artwork shows through cleanly, and the trigger zones are sized to match the story art aspect so the enemies align with the hero walking row.

All the scattered dev-only entry points consolidate behind a single compact red DEBUG button top-left on every screen, replacing the title-screen and Settings → Profile debug surfaces that used to live in the player-facing UI.