docs(physics): implementation plan — unified verbatim-collision (5 slices)
Task-by-task plan for the unified collision-inclusion fix: D1 DAT-only shape
authority + delete mesh-AABB, D3 sphere primitive, D2+D5 obstruction_ethereal
port, D8 RemoveCellsForLandblock, D4+W1 entry-restrictions + dispatch wiring.
Each task: grep-named -> pseudocode -> port -> conformance-test, build+test
green, commit; visual gates batched to the end.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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