diag(track-a): inventory contained Mesa GLX provider stack

[blakinio]

Track A RUNTIME-INFRA — contained Mesa/GLVND/DRI provider inventory

Task: OTC-20260816-track-a-mesa-glx-provider-inventory.
Base: exact trusted main@d3f186414256151c9d5e03f34c5a9026b1fba500.
Execution: one read-only physical support-filesystem inventory on synology-otclient-01; no X server or official client is started.

Input frontier from Draft research only: #416 proved contained GLX server components exist; #417 proved +extension GLX alone does not expose GLX; #418 proved this Xvfb rejects -modulepath. The remaining support question is whether the contained Mesa/GLVND/DRI software-provider stack is complete and which exact provider/search paths exist.

The workflow uses Python stdlib only and fixed contained roots. It inventories named libGL/libGLX/libGLX_mesa/libGLdispatch/libEGL_mesa/GBM/DRM candidates, DRI provider files including swrast_dri.so, direct ELF dependencies, RPATH/RUNPATH, bounded provider/search-path strings, and fixed GLVND/EGL vendor JSON directories.

No /proc inventory, X11/VNC state, official client package/process, canonical lease/registration/session, credentials, network/game/login, Track B or historical #303 surface is observed. runtime_access: read_only, mutation_authorized:false.

Research output remains Draft-only; coordinator promotion is separate.

[blakinio]

Coordinator disposition: CLOSED_SUPERSEDED / provider-stack inventory retained. This Draft supplied useful Mesa/GLVND/DRI inventory that guided the provider-path hypothesis, but #421 directly proved the minimal production-relevant causal input and #427 promoted that stronger result. Preserve this closed PR as discovery provenance; do not merge its stale task state.