test(yaml-ide-gsm): cover non-SSH integration regressions

[kubohiroya]

Summary

Parent: #1156
Epic: #1162

Add post-activation non-SSH SimulationWorkflow / IDE-GSM integration regression coverage using canonical snapshots and mock HTTP/WS infrastructure.

Scope

In

• Scenario, remote, ec2, rsync, and git non-SSH command boundaries.
• Mock HTTP/GraphQL and task-status behavior.
• Validation/import failure cases with zero command network calls.
• Sanitized failures for GraphQL error, FAILED, CANCELED, and disconnect.

Out

• SSH lifecycle start/stop integration.
• remote/ec2 fallback for SSH.
• Production server dependency.
• Result tree materialization.

Acceptance Criteria

• Non-SSH command paths are covered by integration/regression tests.
• Validation/import failures perform zero downstream command calls.
• Retry, alias, and fallback behavior is not introduced.
• Relevant typecheck/test commands exit 0.

Rollback

Revert the tests and any test-only fixtures. No production runtime behavior is changed unless explicitly included in the reviewed diff.

Branch

test/simulation-workflow/non-ssh-integration

[kubohiroya]

2026-08-26 status update: 実機での細かな動作試験へ入る前の棚卸しにより、本Issueは一旦保留とする。

保留理由:

• non-SSH IDE-GSM integration regression coverage は有用だが、直近は実機試験の観測と範囲固定を優先する。
• 実機で確認する non-SSH command 範囲、mock HTTP/GraphQL で固定すべき境界、失敗系の優先度を試験結果に合わせて確定する。

再開条件:

• 実機試験で non-SSH command の回帰テスト化すべき挙動が確定した時点。
• chore(yaml-ide-gsm): complete Step 4 rollout #1461 final rollout の前提として、mock integration coverage を固める必要が出た時点。