LUME CAD Approval Pack - K11 T-Form Audit

Superseded for the current hardware pass by `LUME_CURRENT_BUILD_SPEC.md`, which adds the ZHAOCAILIN top display, Arducam IMX586 mount, K11-era rear pod interface, and approval-v2 STL exports. > Do not use this as the active print plan. It is retained only as an audit trail for the earlier K11 T-form review. This is a repo-grounded audit of the current CAD, STL exports, and prearranged 3MF print plates. It corrects the earlier "31 parts" claim. - Front bar: 500 x 120 x 85 mm rounded enclosure, printed as four shell halves. - Rear pod: centered pod behind the bar for the GMKtec K11, K11 sled, cable bend, airflow, and VESA mount. - Compute: K11 lives in the pod. Do not use the old Jetson AGX Orin sled path. - Sensors: Orbbec Femto Mega/front camera window, two SVPRO brackets, UMA-8 mic rail, LED diffuser, cable backbone. - Top display: 1920 x 440 strip display is represented, but dimensions are still placeholder and not approved. - `renders/approval/approval_form_factor.png` - fresh T-form overview, top view, side/front views, pod exploded, and current top display cutout. - `renders/approval/approval_shell_halves.png` - all four printed shell halves, exterior and interior. - `renders/approval/approval_print_plates.png` - the seven prearranged 3MF plate thumbnails. - `renders/approval/approval_small_parts.png` - active small parts plus flagged legacy/optional pieces.