79c78cc7e1
Two changes after user feedback that externals sit near-but-wrong (shield inset into the hull, thruster floating close): - Scale: the joint table's slots 5–7 are per-axis scale (a GN_ShieldG frame ships at 0.5, GN_Jet FX at 2.4–6.5) and were being ignored, rendering scaled parts at the wrong size. ScenePart now carries `s` and applies R·(S·v)+T. - External placement is fundamentally approximate: a GN_* frame is the mount PIVOT (f105's two GN_ShieldG frames are both on the centreline), while the part's outboard/rotational offset lives in a detail sub-rig / runtime code this static pass can't recover. So assemble_ship gains `include_external`: the hull tier (rou_ nodes) is exact and always drawn; the external tier (bridge / shield / engine at GN_ frames) is opt-in via a "Show external parts" checkbox in the Ships browser, off by default so the clean, correct hull is the default view. The module doc is corrected to the scene-graph mechanism (the old "draw parts untransformed" claim was wrong). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>