Investigate interactive shell screen usage and fullscreen direction

[DaniloNovakovic]

Context

The current interactive shell keeps the game inside a centered card with header/footer chrome and capped dimensions. During Bridge review, the route worked but felt spatially constrained, and future Character Conversation Overlay work may need more room.

This is an investigation/design-spike work item, not an immediate shell rewrite.

Recommended timing: after #90 and #91, or earlier only if their implementation proves the current game card blocks readable staging. Resolve before Concert implementation if Ridge still feels cramped.

Goal

Evaluate whether interactive mode should use more available viewport space, potentially through fullscreen or fuller-bleed layout options, while preserving Ridge readability, mobile controls, safe areas, and overlay ergonomics.

Questions To Answer

• Should Ridge use a fullscreen/fuller-bleed interactive shell instead of the current centered game card?
• Should this apply to all interactive scenes or only side-view exploration scenes like Ridge?
• How do header controls, footer hints, touch controls, scene UI panels, and the Character Conversation Overlay fit in a fuller-screen layout?
• Does fullscreen improve Bridge staging and conversation readability on desktop and mobile?
• What responsive viewport targets need screenshot/browser verification?
• Does changing screen usage require camera/framing changes inside Phaser, or only shell CSS/layout changes?

Acceptance Criteria

• Inspect the current shell layout and constraints, especially src/game/shell/InteractiveApp.tsx and src/game/shell/gameShellLayout.ts.
• Produce a short recommendation: keep current card, adjust caps, add fullscreen mode, or move Ridge to a fuller-bleed shell profile.
• Include concrete trade-offs for desktop, mobile, safe areas, touch controls, and Character Conversation Overlay placement.
• If making a prototype, keep it small and reversible behind a local/layout flag or focused branch.
• Verify any prototype with browser screenshots at representative desktop and mobile viewports.
• Do not permanently rewrite the shell unless the issue conclusion and evidence clearly support it.

Boundaries

• Do not mix this with Bridge art/assets.
• Do not change gameplay route state.
• Do not hide required controls or make mobile input less reachable.
• Do not assume fullscreen is automatically correct; compare it against smaller layout adjustments.

Recommended Sequence

1. Merge PR [codex] Implement Ridge Bridge tracer slice #89 / finish Bridge Tracer Slice.
2. Complete Bridge Visual Coherence Pass before Concert #90 Bridge Visual Coherence Pass.
3. Complete Ridge Character Conversation Overlay #91 Ridge Character Conversation Overlay.
4. Do this investigation if the overlay/staging feels cramped or before Concert if screen usage remains a blocker.
5. Begin Concert Area implementation after the layout direction is no longer blocking.

Source Docs

• CONTEXT.md: Interactive Shell Screen-Usage Investigation.
• docs/game-design/ridge/areas/01-bridge/README.md: post-tracer sequence.
• docs/runtime-architecture.md and docs/runtime-modes.md: shell, scene UI, and runtime mode boundaries.