Remove copied binder backup subsystem

[fredporter]

Summary

• remove the isolated binder.bak task-management copy from the usync example
• remove duplicated hand-written MCP servers, generated file-splitter modules, and copied tests
• remove ignored bytecode caches from the local directory
• retain no compatibility path because this backup subsystem had no supported callers

Verification

• full workspace build passes
• 188 Node tests pass
• 198 Python tests pass, with 33 existing skips and 2 existing warnings
• repository audit finds no binder.bak, task_mcp_server, or Usync/binder references