Add visual highlight effect for newly available actions

[PipFoweraker]

Summary

When new actions become available (unlocked by meeting requirements), they should have a visual highlight effect until the player interacts with them.

Proposed Implementation

• Track which actions player has 'seen' or interacted with
• New/unseen actions get a subtle glow or pulsing border
• Effect disappears after:
  • Player hovers over the action, OR
  • Player uses the action, OR
  • Next turn starts (optional)

Example Use Cases

• Player publishes first paper → 'Submit Paper' action unlocks → highlighted
• Player reaches 30 reputation → 'Strategic' submenu unlocks → highlighted
• New hire types become available after certain turn → highlighted

Technical Considerations

• Need to track 'seen' actions in GameState or separate tracking
• Could use shader effect or animated border
• Should be subtle, not distracting

Priority

Nice-to-have - helps player discovery of new options