Build Garden roster and Gate prep UI

[JOY]

Summary

Add the first player-facing UI for the living roster and mission preparation loop.

Scope

• Show 5-10 important NPC Frames in a Relay Yard roster view.
• Show role, level, TIME, injury, relationship hint, and current state.
• Add Gate mission selection and NPC ally selection placeholders.
• Keep debug-only fields behind a debug toggle.

Acceptance Criteria

• In Play Mode, the player can inspect a persistent NPC Frame from the roster.
• The roster distinguishes public player-facing state from debug-only state.
• The first Gate prep card can show risk, expected TIME exposure, and reward placeholders.
• UI remains readable at common Game view resolutions.

References

• docs/design/25-core-loop-v1.md
• docs/design/26-ai-npc-backend-client-roadmap.md

[JOY]

Implementation packet added in PR #188: docs/design/45-alpha-backlog-execution-packets.md.

Use that packet as the build contract for this issue: goal, minimum data contract, Unity/backend surface, verification, and cut line. This comment does not close the issue; implementation still needs its own PR and runtime evidence where applicable.