* ci: route trusted-author fork PRs and no-checkout jobs to the ECS pool
Fork PRs whose author has write access (OWNER/MEMBER/COLLABORATOR association) now run Linux CI on the self-hosted ECS pool instead of the saturated GitHub-hosted quota, and bot workflows that check out no code move to ECS unconditionally. Everything stays gated on the MAINTAINER_ECS_RUNNER_DISABLED kill-switch.
* ci: address review — real write-permission routing, watchdog independence, timeouts
Route the triage agent on the collaborator-permission API result computed by authorize instead of the coarse author_association, which admits org members and read-only collaborators; the two permission-gate jobs revert to the same-repo guard. Keep the fleet watchdog and the CI-failure reporter hosted so they stay independent of the pool they watch. Add missing timeouts, wipe serve-ab's reused workspace, and pin the routing logic with drift and negative-case tests.
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Co-authored-by: 易良 <1204183885@qq.com>