[P3] Frontend performance budgets + Lighthouse CI

[hazeliscoding]

Problem

No bundle size or time-to-interactive targets are defined. With Chart.js, ng2-charts, and Angular loaded, the bundle could already be substantial.

Requirements

• Add budgets to angular.json (initial bundle < 250KB, lazy chunks < 80KB)
• Add Lighthouse CI to the GitHub Actions pipeline
• Set performance score threshold (e.g. >= 80)
• Generate bundle analysis report on CI

Acceptance Criteria

• CI fails if bundle size exceeds the defined budget
• Lighthouse CI runs on every PR with a minimum score threshold
• Bundle analysis artifact is available for inspection
• Current bundle size is documented as a baseline

References

• Roadmap §12 — Frontend Engineering