b986f49moved the_mesh to PSRAM and changed MyMesh.h's extern to 'MyMesh&', but the Tanmatsu has its OWN main.cpp (tanmatsu/main/main.cpp, separate from src/main.cpp) that still declared a plain 'MyMesh the_mesh' global — a conflicting declaration that broke the P4 build (only the S3 envs were built forb986f49). Apply the same placement-new- into-PSRAM + reference pattern here; the P4's 32 MB PSRAM gets the same DRAM win. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>