fix(control): repair repository cache origin

[AntoineToussaint]

Closes #277.

PrepareRepositoryCheckout already owns and repairs its named cache projection. This change extends that recovery to the precise case where the cache is a valid Git repository but has no origin:

• enumerate configured remotes through Codefly's isolated Git environment
• add origin from the typed request's authoritative repository URL only when absent
• preserve the existing fail-closed behavior for a present but mismatched origin
• continue the normal exact-revision fetch, forced checkout, and clean flow

The production-capability test uses a real repository and bare remote. It proves missing-origin repair, exact revision, clean checkout, idempotent retry, and rejection of a mismatched existing source.

Verification:

• focused checkout lifecycle tests: pass
• go vet ./...: pass
• go test ./... -count=1: pass
• git diff --check: pass

No Git workaround is added to Mind; the capability remains owned by Codefly.