fix env-scoped app status rendering

[JamesSprow]

Summary

• stamp Building onto the active EnvironmentStatus during git builds
• resolve UI status from env-specific build run + env phase instead of app-global phase
• share optimistic rebuild/redeploy phase overrides across canvas, list, and drawer

Testing

• make test
• npm run check
• npx vitest run ui/src/lib/types.test.ts
• go test ./internal/controller/...