[raykholo]

Port of tangency-labs#12651 (laser-weld corner relief, by admin.greg / @ocpistol-bec) onto the surfaces-first develop in tangency-labs#9245.

What it does

• New corner relief shape laser_weld ("Laser weld" in the dialogs).
• It closes the mitre seam tight, the same way Tear does, and cuts a round hole the size of corner_relief where the bends cross. The hole is centred at the seam root, where the bends' tangent lines meet on the shared panel. The corner can't tear as it bends, and the seam is left ready to weld.
• If the hole would be smaller than MIN_RELIEF, the corner falls back to Tear and adds a note.
• If the flanges aren't closed toward each other, it falls back to a notch and adds the note "a laser-weld corner needs its flanges closed toward each other".

How it differs from tangency-labs#12651's original V tabs

On tangency-labs#9245 every corner rip is already Lap::Miter { gap }. Mitre-cut tabs at the seam ends would therefore come out identical to Tear. What a weld corner adds is the hole at the root, which stops tearing. So this port is Tear's closed mitre seam plus a corner-relief-sized round hole. This matches the line for laser weld in your table: "the one to add, on the same corner code".

Enum touch across the three vendored crates

CornerRelief::Weld is added in:

• solidcore/crates/solidcore-record/src/develop.rs (the record enum)
• solidcore/crates/solidcore/src/develop/sheet.rs (the kernel enum)
• solidcore/crates/solidcore-convert/src/develop.rs (the mappings both ways)

develop/layout.rs gains weld_cut: corner_cut returns it for Weld. The hole is centred at the crossing of the zones' shared-panel-side edges. Its two arcs meet inside the wedge between the zone ends.

Also touched

schema pattern, shape-list error strings, manage_rules help, dialog labels, pending locale strings (en, ar, de, he, ja, ko, vi, zh), book guide, skill reference, face names (Weld walls are named like Tear's).

Tests (buildq)

• engine a_laser_weld_corner_closes_the_seam_and_holes_its_root: 1 passed. On the 90° alu tray with corner_relief 1 mm, it checks:
  • the DXF holes are r = 0.5 at (3,3), (117,3), (117,87) and (3,87)
  • the area each hole takes lies between the chord bound and πr²
  • the volume removed versus Tear equals twice the area taken, within 1e-3
  • the volume is above the notch case
  • unfold, refold and reopen keep the volume
• engine tear / corner_reliefs / closed_corners / schema::sheet: 18 passed
• doc corner_relief: 1 passed
• ui-egui sheet: 71 passed
• solidcore develop: 40 passed

Credit: admin.greg (@ocpistol-bec) for the laser-weld relief and the original PR.