feat: Add isReady state property

[FrederikBolding]

Adds a lazily populated isReady state property that is populated as a side-effect of ensureCanUsePlatform (renamed from assertCanUsePlatform).

---

Note

Introduces isReady to SnapController state, lazily populated via new #ensureCanUsePlatform, and updates flows/tests accordingly.

• State/Metadata:
  • Add state.isReady (default false); include in includeInStateLogs and includeInDebugSnapshot; not persisted/used in UI.
• Platform readiness:
  • Replace #assertCanUsePlatform with #ensureCanUsePlatform that waits onboarding, sets isReady based on disableSnaps, and asserts availability.
  • Call #ensureCanUsePlatform in init(), updateRegistry(), startSnap(), installSnaps(), #updateSnap(), and handleRequest().
  • Reset isReady to false in clearState().
• Tests:
  • Add test verifying SnapController:init sets isReady.
  • Update expectations to include isReady in debug/state logs and post-clearState state, and minor timing adjustments.

^{Written by Cursor Bugbot for commit 2df985d. This will update automatically on new commits. Configure here.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.30%. Comparing base (1e95bcd) to head (2df985d).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3778   +/-   ##
=======================================
  Coverage   98.29%   98.30%           
=======================================
  Files         420      420           
  Lines       12232    12238    +6     
  Branches     1897     1898    +1     
=======================================
+ Hits        12024    12030    +6     
  Misses        208      208           

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[cryptodev-2s]

LGTM!