feat: add vedh observability tooling and board polish

[dylanlott]

Summary

This PR bundles three coherent pieces of local work that were already sitting uncommitted in the vedh repo and prepares them for review as a single branch:

1. Local observability tooling

   • adds a local Prometheus + Grafana stack under monitoring/
   • adds Makefile support for bringing the stack up/down
   • documents the local observability flow in the README
   • commits the example observability env file while keeping real local env files ignored
   • ignores Rust smoke build output under tools/smoke/target/

2. Board / score view polish

   • refreshes the card presentation on the board
   • improves the overall board layout and play surface styling
   • upgrades the score view UI and loads the active game from the route/auth context

3. NFT card tracking implementation plan

   • adds the detailed planning doc for the future NFT card-tracking workstream

Why

• makes the existing local work reviewable instead of leaving it stranded in a dirty worktree
• separates meaningful source/docs changes from local generated noise
• gets vedh into a cleaner GitHub-backed state for follow-up work

Verification

• npm --prefix app run type-check
• git diff --check origin/main..HEAD

Notes

• no generated Rust smoke artifacts are included in the branch
• monitoring/.env.observability stays ignored; monitoring/.env.observability.example is committed as the shareable template