Sprint 11/12/13 — 선택하이라이트 + 저장/로드 + Tauri앱 스켈레톤

Sprint 11 (Selection highlight + 단면 UI):
- FeatureDraw: CPU 정점 저장, update_highlight() — 선택 시 yellow-orange
- 렌더 루프: background mesh(지면+선형) + 피처별 독립 draw call 분리
- SceneParams: GirderSectionType (PscI / SteelBox), show_alignment
- egui: 단면형식 ComboBox, 선형표시 checkbox
- SteelBox 단면 지원 (span 비례 자동 치수)
- build_background_scene(): 지면+선형만 반환

Sprint 12 (Project save/load):
- project_file.rs: ProjectFile struct, to_params/from_params, save/load JSON
- egui: 💾 저장 / 📂 불러오기 버튼
- projects/ 폴더 자동 생성

Sprint 13 (Tauri app skeleton):
- crates/app/: Cargo.toml + main.rs (Tauri v2 통합 scaffold)
- 기동 시 PureRustKernel 동작 검증
- Tauri setup checklist 주석으로 문서화
- workspace에 cimery-app 추가

cargo check --workspace 통과

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cimery/crates/app/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name    = "cimery-app"
+version.workspace = true
+edition.workspace = true
+description = "cimery desktop application (Tauri v2 + Leptos UI)"
+
+[features]
+# Geometry backends
+occt = ["cimery-kernel/occt"]
+
+[dependencies]
+cimery-core        = { workspace = true }
+cimery-ir          = { workspace = true }
+cimery-dsl         = { workspace = true }
+cimery-kernel      = { workspace = true }
+cimery-incremental = { workspace = true }
+cimery-evaluator   = { workspace = true }
+cimery-usd         = { workspace = true }
+
+serde      = { workspace = true }
+serde_json = { workspace = true }
+log        = { workspace = true }
+env_logger = { workspace = true }
+
+# Tauri v2 (ADR-001: desktop packaging)
+# Uncomment when setting up Tauri project:
+# tauri = { version = "2", features = ["devtools"] }