feat: Implement spinkube SpinApp CRD health checks

[lukepatrick]

PR implements healths check for core.spinkube.dev/SpinApp

core.spinkube.dev/SpinApp:

• health.lua
• tests

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• The title of the PR states what changed and the related issues number (used for the release note).
• The title of the PR conforms to the Toolchain Guide
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).
• My new feature complies with the feature status guidelines.
• I have added a brief description of why this PR is necessary and/or what this PR solves.
• Optional. My organization is added to USERS.md.
• Optional. For bug fixes, I've indicated what older releases this fix should be cherry-picked into (this may or may not happen depending on risk/complexity).

[bunnyshell]

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Available commands (reply to this comment):

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• ❌ /bns:delete to try again to remove the environment

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.02%. Comparing base (b8051c6) to head (8b67790).
⚠️ Report is 417 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #21896   +/-   ##
=======================================
  Coverage   60.01%   60.02%           
=======================================
  Files         343      343           
  Lines       57890    57890           
=======================================
+ Hits        34744    34746    +2     
+ Misses      20362    20359    -3     
- Partials     2784     2785    +1     

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