fix(ctf): keep spare teardown retryable after dispatch failure

[Brad-Edwards]

Summary

• Preserve a spare range owner and nonterminal pool status when teardown dispatch fails or its range ID has not resolved yet, so a later cleanup attempt can retry.
• Resolve a late range ID from the recorded request before dispatching teardown.
• Add regression coverage for transient dispatch failure and delayed range resolution.

ADR Impact

• No ADR impact

ADRs touched: None.

Exceptions added or renewed: None.

Guardrail Changes

• No guardrail files changed

Guardrail files changed: None.

Verification

• Full ADR guard passed.
• Import-linter and Ruff checks passed.
• Relevant CTF tests passed (128 tests across spare cleanup, recovery, lifecycle, capacity, and teardown).
• Docs updated where behavior or enforcement changed (not applicable; this restores retryability on an error path).

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud