Improve Stream Deck key readability

[danielcompton]

Summary

Before:

After:

• Make agent titles bigger, and allow them to wrap across three lines
• Move agent-state indicator to top left and context usage to top right
• Increase contrast of working and inactive states
• Stagger animation phases by agent slow so the working animations aren't synchronised with each other
• Enlarge standalone keycap labels
• Update agent preview assets and renderer coverage

Why

The existing labels and state marks are difficult to distinguish on the physical Stream Deck Mini. These changes use more of the available key area, show more of each task title, and make working versus inactive agents easier to recognize at a glance.

Impact

Agent titles now scale up to 27px on one line, 26px on two lines, and 24px on three lines. State and context indicators occupy consistent corners, and standalone actions use larger, heavier labels. The rendering remains theme-aware for both light and dark Codex layouts.

Validation

• npm run check
• npm test — 135 passed, 1 expected Windows-only skip
• native 144×144 previews inspected for agent states, long titles, action labels, and staggered animation frames