NURBS Slice F: curved patch trim and true split

[w1ne]

Summary

• Rebuilds the forked OCCT wasm dependency to kcad-v0.24.0 with BRepFeat_SplitShape available, and verifies the installed binary exposes it.
• Replaces planar-only surface trim lowering with BRepAlgoAPI_Section + BRepFeat_SplitShape imprinting for clean curved patch trims.
• Changes Surface.split(by) to return both halves as [Surface, Surface], updates docs/MCP/list_api/skills, and bumps version to 0.15.0.

Closes #528

Verification

• node wasm probe: BRepFeat_SplitShape present; BRepAlgoAPI_Section present
• npx vitest run tests/unit/intent/surfaceTrim.test.ts
• npx vitest run tests/unit/backends/occt/surfaceTrim.test.ts
• npx vitest run tests/integration/mcp/listApi.driftSentinel.test.ts tests/integration/mcp/finishSurface.test.ts tests/unit/cli/skill.test.ts tests/unit/diagnostics/codes.test.ts tests/unit/diagnostics/emittedCodesAreCatalogued.test.ts
• npm run typecheck
• npm run lint (exit 0; existing unused-disable warnings remain)