Polish responsive player and display layouts

[kevinatlee]

Summary

• tighten spacing above the player word-entry field
• compact the active player board on wide screens while preserving lobby and display sizing
• center the player round action without adding vertical margin
• scale display result cards from one through four columns based on player count
• stack portrait display sections in puzzle, players, and right-side order
• add focused component and stylesheet coverage for the responsive layout rules

Validation

• privacy, formatting, lint, and typecheck
• focused client tests and full test suite (808 tests)
• application and production builds
• game-data verification, including client build
• dependency audit (0 vulnerabilities)
• production smoke test

Acceptance gate

Keep this PR in draft until the exact head is published to :test and physically evaluated on the target player/display layouts.