fix(compute-providers): add provider diagnostics

[edersonbrilhante]

Description

Centralize compute-provider names and defaults, replace EC2 plugin literals with the canonical provider value, and add structured provider/capability diagnostics at pool, scale-up, scale-down, webhook, and registry boundaries.

Diagnostics avoid secrets, JIT configuration, signed webhook data, and full EC2 request payloads. Focused tests also cover provider resolution, registry consistency, capability selection, and sensitive logging behavior.

Test Plan

• Passed focused compute-provider tests: 298/298
• Passed control-plane tests: 345/345
• Passed webhook tests: 83/83
• Passed lint for compute-providers, control-plane, and webhook
• Passed formatting validation for all changed TypeScript files
• Passed control-plane and webhook typechecks
• Compute-provider typecheck still reports pre-existing errors in vitest.config.ts and vitest.base.config.ts

Related Issues

N/A

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None