nx_compile_perf.nx

nx_compile_perf.nx -- the Engineer's COMPILE-TROUBLESHOOTING capability (operator: "if compile is slow research how teams address this to troubleshoot quickly"). Grounded in the established practice (ccache, incremental builds, parallel -j, clang -ftime-trace / gcc -ftime-report profiling, bisection): - the Engineer picks the right LEVER by symptom: a HANG -> bisect-to-function + split (nx_hang_resolve); SLOW-but-completes -> CACHE (skip unchanged modules by source-hash, the #1 win since the team recompiles whole files), + INCREMENTAL (only changed), + PARALLEL (-j), + PROFILE (find the hot fn). - all under the operator's SLA: troubleshoot in <=3 steps; a CACHE HIT is the 1-step optimal (~instant). license_tier: ORIGINAL Pairs with nx_hang_resolve + nx_build_safe. Refs: ccache; clang -ftime-trace (aras-p.info); gcc -ftime-report/-H; Clang Build Analyzer.