feat: add pause task setup command

[0xth4nh]

Summary

• add make setup-pause-task network=<network>
• add a reusable active/evm/make/pause-bridge.mk workflow that only generates pauser-service signatures
• reuse an existing active pause task across network rollout dates, with TASK_ID=<task-id> for explicit selection
• generate network-scoped signer instructions and signature output
• update repository documentation for the signing-only flow

Testing

• CI creates mainnet and Sepolia configs in an isolated temporary repository and dry-runs sign-pause
• git diff --check

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/2	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 2 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 2 2 1 if commit is unverified 0 Sum 2

[cb-heimdall]

Review Error for mw2000 @ 2026-09-14 15:28:04 UTC
User failed mfa authentication, see go/mfa-help

[leopoldjoy]

Could we keep **/signatures-pause.txt (and the temporary outputs) ignored, since this target generates sensitive bearer signatures inside the repository?

[leopoldjoy]

Could we still generate a minimal task-root FACILITATOR.md describing the signing and pauser-service handoff, so generated tasks satisfy the explicit facilitator-guide requirements in AGENTS.md without restoring manual execution?

[linear]

CHAIN-5387