test(frontend): unblock 7 specs from jsdom

[Yicong-Huang]

What changes were proposed in this PR?

Most specs that #4866 listed as needing Vitest browser mode actually weren't blocked by jsdom's missing layout — they were tripping on infra and migration leftovers. Fix the root causes so they run under jsdom; narrow #4866 to the real layout-dependent jointjs paper suite.

Three changes:

• vitest.config.ts inlines monaco-breakpoints so its import './style.css' goes through Vite instead of Node's ESM loader (which crashes on .css).
• jsdom-svg-polyfill.ts stubs requestIdleCallback (Chrome-only).
• 6 specs get declarations → imports (post-refactor(frontend): convert all components to standalone #4873 standalone) and beforeEach(waitForAsync) → beforeEach(async) (the ProxyZone wrapper in test-zone-setup.ts only covers it/test).

Plus three small per-spec fixes: vi.spyOn → .mockImplementation(() => {}) in code-debugger (vitest spies call through by default, unlike Jasmine), innerText → textContent in operator-property-edit-frame (jsdom's innerText is layout-dependent), and it.skip for the 2 drag-drop tests that genuinely need real geometry.

After this, the only spec excluded for jsdom-vs-real-browser reasons is workflow-editor.component.spec.ts.

Any related issues, documentation, discussions?

Part of #4861. Narrows #4866 to the jointjs paper suite + 2 drag-drop geometry tests.

How was this PR tested?

yarn ng test --watch=false: 251 pass, 11 skip, 2 todo. yarn format:ci clean.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Opus 4.7 (1M context)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 42.58%. Comparing base (34b004d) to head (7597811).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #4950      +/-   ##
============================================
+ Coverage     42.49%   42.58%   +0.09%     
  Complexity     2177     2177              
============================================
  Files          1005     1031      +26     
  Lines         37422    38096     +674     
  Branches       3911     3997      +86     
============================================
+ Hits          15901    16223     +322     
- Misses        20558    20861     +303     
- Partials        963     1012      +49     

Flag	Coverage Δ
frontend	33.00% <ø> (+0.73%)	⬆️

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