Occupy GDB's executable slot with its owned /proc/self/exe while loading a
core, then discard it before mapping queries. Select the validated decoder
architecture explicitly and restrict build-ID lookup to the owned empty path.
Preserve cancellation reasons at debugger admission.
Keep the original fixture executable present during syscall verification and
add Debian 13 / GDB 16 coverage alongside Ubuntu 24.04 in the CI definition.
Validation: controlled producer regressions and request-profile controls;
real GDB 16.3 / strace on Linux arm64 shows the old bridge opening the
recorded executable and the fix returning the same mapping without that
access. A cross-architecture gdb-multiarch probe confirms profile selection.
The plugin was controlled; full native pwndbg and Linux x64 remain unverified.
No performance improvement claimed; task tokens/CPU/family memory unmeasured.
Fixes#4914
morluto
5bf4fffc1b