Split monolithic mirror.go into focused single-responsibility modules#11

Draft

Copilot wants to merge 3 commits intomasterfrom

copilot/split-and-organize-logic

Commits on Oct 29, 2025

Initial plan
Copilot
committed
Split and organize logic into focused files

Copilot
and
wzshiming
committed
Fix code review issues

Copilot
and
wzshiming
committed