Reuse stable-file hashing and exact cleanup leases for target verification, join admitted call workflows before tracer close, and block replacement work while descriptor cleanup remains unresolved. Preserve physical failures, exact cancellation reasons and completed call facts; remove the duplicate reader and AbortError-name heuristic.
Validate real inert-file cleanup controls and controlled tracers through provider and MCP boundaries. No LLDB execution, real OS close-failure or Windows qualification.
Refs #4740