[Backport stable-25-2] initial scd2

[ydbot]

Description

Backport of #27430 to stable-25-2.

[ydbot]

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-27430-to-stable-25-2
git worktree add --checkout .worktree/backport-27430-to-stable-25-2 backport-27430-to-stable-25-2
cd .worktree/backport-27430-to-stable-25-2
git reset --hard HEAD^
git cherry-pick -x 4b6712c57f77cc190a51838388fa14137cc4f1eb
git push --force-with-lease

[github-actions]

⚪ 2025-11-06 12:58:28 UTC Pre-commit check linux-x86_64-relwithdebinfo for adc16ba has started.
⚪ 2025-11-06 12:58:32 UTC Artifacts will be uploaded here
⚪ 2025-11-06 13:00:52 UTC ya make is running...
🟢 2025-11-06 13:00:57 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-11-06 13:01:03 UTC Build successful.

[github-actions]

⚪ 2025-11-06 12:58:32 UTC Pre-commit check linux-x86_64-release-asan for adc16ba has started.
⚪ 2025-11-06 12:58:46 UTC Artifacts will be uploaded here
⚪ 2025-11-06 13:01:04 UTC ya make is running...
🟢 2025-11-06 13:01:10 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-11-06 13:01:16 UTC Build successful.

[github-actions]

🟢 2025-11-06 13:00:42 UTC The validation of the Pull Request description is successful.