perf(ui): lazy-load routes and Azure Maps assets [5/5]

[Anthony Cintron (prbatero)]

Summary

Part 5 of 5 in the project layer-loading performance stack. Remove unrelated map and route startup work from the project page and record final end-to-end measurements.

Changes

• Code-split application pages with route-level lazy loading.
• Load Azure Maps control, drawing, styles, and swipe support only before map-dependent routes mount.
• Remove blocking global Azure Maps tags from index.html.
• Expand browser timing diagnostics and correct request-start accounting.
• Reconcile the feature specification with tested cache, transaction, concurrency, and performance semantics.

Testing

• Full hastelib suite: 581 passed.
• Performance-stack API suite: 50 passed; two independent security cases are owned by fix(api): reject client-supplied workflow state #184.
• Queue suite: 6 passed.
• UI suite: 121 passed.
• New UI utilities: 100% line, branch, and function coverage.
• Changed UI files pass ESLint with zero warnings; production Vite build passed.
• Black, isort, flake8, and detect-secrets passed across the stack.

Measurements

• 50×5 fixture: 603 → 7 logical data-layer calls.
• Uncached API: 1.85 s p50 / 2.00 s p95.
• Fresh process cache: 9.1 ms p50 / 12.2 ms p95 with zero logical calls.
• Production project page: 2.12 s TTI, one initial request, 58 ms post-response render.
• Terminal project: zero polls during a 26-second window; active project: one non-overlapping conditional poll returning 304.
• Main JS chunk: 1.49 MB → about 120 KB.

Stack

• Depends on: perf(ui): deduplicate refreshes and poll active jobs only [4/5] #188.
• This PR: 5/5, based on prbatero/feat/perf-project-details-ui.
• Deploy this head to test the complete five-PR performance stack.
• Independent security fix fix(api): reject client-supplied workflow state #184 is not included in this head.

Review Notes

The seven-call metric counts logical data-layer operations, not Azure REST transactions. Blob downloads remain proportional to records returned. The <1.5 s uncached API and <2 s TTI targets remain open.