LATX, KZT: add per-library-family wrapper controls

[LaurenIsACoder]

Summary

• classify the existing KZT wrappers into dependency-aware library groups
• keep group names, bit positions, stable or experimental status, and dependencies in one developer-facing kzt-group-list.h registry
• add one selector, LATX_KZT_LIBS, for stable, exact, and delta selections
• keep disabled groups on the guest translation path instead of loading their host wrappers
• apply the resolved selection consistently to system, user, per-application, environment, command-line, static/direct-loader, and deferred Wine paths
• add LATX_KZT_LOG=1 diagnostics for the effective group set and per-library wrapper eligibility
• add latx-x86_64 --kzt-libs so the installed binary reports its groups, stability status, dependencies, and accepted syntax
• expose -h and --help in product builds so the selector and query are discoverable

The README points users to --kzt-libs instead of duplicating a library-group inventory that would become stale. This PR contains only product, configuration, and documentation changes; it does not add test or audit programs.

Behavior

Normal use remains simple:

LATX_KZT=1

Targeted rollback and debugging use the same selector:

# Remove one group and groups that depend on it from the stable set
LATX_KZT=1 LATX_KZT_LIBS=-x11

# Use one group and its required dependencies
LATX_KZT=1 LATX_KZT_LIBS=x11

Dependencies are resolved before wrapper loading. Disabling a dependency prunes dependent groups, preventing a host object from crossing into a guest-translated dependency. Unknown groups, mixed selector forms, and invalid LATX_KZT or LATX_KZT_LOG values disable KZT for that process and report the reason instead of enabling an unintended wrapper set.

Library-group eligibility only means that LAT may use the registered KZT wrapper. It does not imply that every function in that library reaches a host implementation; custom wrappers may deliberately re-enter guest execution.

Validation

Validated on LoongArch64 with the normal tests=auto product configuration:

• incremental product build of latx-x86_64: passed
• final no-work rebuild check: passed
• -h and --help: exit 0 with identical output
• help includes LATX_KZT_LIBS, -latx-kzt-libs, and -kzt-libs
• --kzt-libs: exit 0 without a guest program
• valid selections stable, x11, and -x11: exit 0 with the expected dependency closure
• invalid group, LATX_KZT=3, and LATX_KZT_LOG=2: KZT disabled with an explicit reason; guest execution continued successfully
• per-application configuration for true: selected -x11 and resolved to core
• real local X.Org display :0: gtkperf completed with LATX_KZT=0, the stable set, LATX_KZT_LIBS=-x11, and LATX_KZT_LIBS=x11
• enabled X11 runs selected the existing libX11, libX11-xcb, and libxcb-render wrappers; the disabled run kept them on the guest path
• no RenderBadPicture, new X Error, SIGSEGV, SIGILL, or SIGABRT was observed

Final product binary SHA-256:

d66579f5461f16c982e279c6379a9322cdb1b1cd0cc9b54d6df1865cf7a1884f