scripts: confirm before restarting all Core pods at once

[matanl-starkware]

Restarting every Core pod simultaneously brings all consensus validators down at
once and can halt the chain. In the parallel (ALL_AT_ONCE) restart flow, prompt
the user for an explicit y/n confirmation when the service is Core, and abort the
restart if they decline. Non-Core services are unaffected.

Co-Authored-By: Claude Opus 4.8 (1M context) noreply@anthropic.com

[cursor]

PR Summary

Low Risk
Operator-facing guardrail in prod restart tooling only; reduces accidental consensus outage risk without changing restart logic after confirmation.

Overview
Adds a safety gate in the parallel (ALL_AT_ONCE) restart path in restarter_lib: when the service is Core, the operator must confirm via wait_until_y_or_n before every Core pod is restarted at once; declining aborts with exit code 1 and no pod deletes. Gateway and other non-Core services keep the existing behavior with no extra prompt.

Tests stub the prompt for existing Core parallel cases, and add coverage for decline → abort and non-Core → no prompt.

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[matanl-starkware]

• scripts: make --service a required argument #14306
• scripts: confirm before restarting all Core pods at once #14305 👈 (View in Graphite)
• scripts: add Committer to Service options #14304
• scripts: clean up restart-strategy and service help output #14303
• scripts: restart and wait on nodes in parallel #14302
• scripts: make metrics gate() thread-safe #14301
• scripts: add run_in_parallel helper for prod ops #14300
• ci: fix hybrid system test for prod-script changes and k3d install #14317
• main

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[reviewable-StarkWare]

This change is 

[ron-starkware]

@ron-starkware reviewed 2 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on matanl-starkware).

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[matanl-starkware]

@ron-starkware — next 🙏 #14304 merged, so this rebased onto main and its Reviewable check reset. Re-approve this revision when you can? (Rebase only — no code changes.)