Add bounded deploy recovery dry-run action

[cbusillo]

Summary

• add a Launchplane-owned, dry-run-only GitHub Action for exact legacy generic-web deploy reservation inspection
• reconstruct the legacy deploy idempotency key from the original run ID and attempt inside the action
• delegate OIDC and HTTP handling to the existing shared request action
• expose only the seven bounded recovery evidence fields

Safety

• no apply mode or mutation route
• rejects unknown request fields, including apply
• suppresses the raw response body
• does not return the original idempotency key, provider target, reconciliation key, or payload

Validation

• uv run --extra dev python -m unittest tests.test_generic_web_deploy_recovery_action
• uv run --extra dev launchplane ci unittest-shard local (2,944 targets, 12/12 shards)
• config-authority changed-files gate
• scoped Ruff and format checks
• node --check
• PyCharm changed-files inspection: zero findings
• git diff --check

Related: #2167