cimery Sprint 1 — Rust 워크스페이스 + 전 계층 파이프라인

8개 크레이트 구현, cargo test 32개 전부 통과:
- core: Mm/M 단위 newtype, UnitExt 리터럴, FeatureError
- ir: GirderIR + 전 단면 파라미터(PSC-I/U/SteelBox/PlateI) serde JSON
- dsl: Girder builder + 검증 (경간 범위·count·spacing)
- kernel: GeomKernel trait + StubKernel (box mesh, AABB)
- incremental: dirty-tracking IncrementalDb (salsa 업그레이드 경로 주석)
- evaluator: 상태 없는 IR→kernel 브리지
- usd: USDA 1.0 텍스트 익스포트 (CimeryBridgeAPI·GirderAPI schema)
- viewer: wgpu 22 + winit 0.30 컬러 삼각형 (Sprint 1 proof-of-concept)

Sprint 2 다음 단계:
- opencascade-rs로 StubKernel 교체 (실제 PSC-I sweep)
- viewer에서 Girder Mesh 렌더 + 카메라 orbit

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

cimery/crates/incremental/src/lib.rs

@@ -0,0 +1,176 @@
+//! cimery-incremental — incremental computation layer.
+//!
+//! ## Sprint 1: manual dirty-tracking
+//!
+//! Uses a `HashMap` cache + `HashSet<FeatureId>` dirty set.
+//! Query granularity: **Feature-level** (one dirty entry per Feature instance).
+//!
+//! ## Sprint 2 upgrade: salsa
+//!
+//! Will be replaced by [salsa](https://github.com/salsa-rs/salsa)-based queries
+//! once the API is confirmed stable for both WASM (web) and native (desktop)
+//! targets (ADR-002 D). Key design intent preserved:
+//! - Feature unit = salsa query granularity.
+//! - Lazy/reactive: only invalidated features recompute (ADR-002 B).
+//! - Cache is keyed by `FeatureId`; invalidation is triggered by `set_*` calls.
+
+use cimery_ir::{FeatureId, GirderIR};
+use cimery_kernel::{GeomKernel, KernelError, Mesh};
+use std::collections::{HashMap, HashSet};
+use std::sync::Arc;
+
+// ─── IncrementalDb ────────────────────────────────────────────────────────────
+
+/// Incremental computation database.
+///
+/// Holds one geometry kernel and one cache per Feature type.
+/// In Sprint 2 this becomes a salsa `Database` impl.
+pub struct IncrementalDb<K: GeomKernel> {
+    kernel:     Arc<K>,
+    girders:    HashMap<FeatureId, GirderIR>,
+    mesh_cache: HashMap<FeatureId, Arc<Mesh>>,
+    dirty:      HashSet<FeatureId>,
+}
+
+impl<K: GeomKernel> IncrementalDb<K> {
+    pub fn new(kernel: K) -> Self {
+        Self {
+            kernel:     Arc::new(kernel),
+            girders:    HashMap::new(),
+            mesh_cache: HashMap::new(),
+            dirty:      HashSet::new(),
+        }
+    }
+
+    // ── Writers ────────────────────────────────────────────────────────────
+
+    /// Insert or update a Girder. Marks the feature dirty and evicts mesh cache.
+    pub fn set_girder(&mut self, ir: GirderIR) {
+        let id = ir.id;
+        self.girders.insert(id, ir);
+        self.mesh_cache.remove(&id);
+        self.dirty.insert(id);
+    }
+
+    // ── Readers ────────────────────────────────────────────────────────────
+
+    /// Query the mesh for a Girder.
+    ///
+    /// - Cache hit (not dirty) → returns `Arc<Mesh>` without recomputation.
+    /// - Cache miss or dirty → calls kernel, updates cache, clears dirty.
+    pub fn girder_mesh(
+        &mut self,
+        id: &FeatureId,
+    ) -> Result<Arc<Mesh>, KernelError> {
+        // Cache hit path (not dirty)
+        if !self.dirty.contains(id) {
+            if let Some(cached) = self.mesh_cache.get(id) {
+                return Ok(Arc::clone(cached));
+            }
+        }
+
+        // Compute path
+        let ir = self.girders.get(id).ok_or_else(|| {
+            KernelError::InvalidInput(format!("unknown FeatureId: {}", id))
+        })?;
+        let mesh = Arc::new(self.kernel.girder_mesh(ir)?);
+        self.mesh_cache.insert(*id, Arc::clone(&mesh));
+        self.dirty.remove(id);
+        Ok(mesh)
+    }
+
+    /// Raw IR lookup (no computation).
+    pub fn get_girder(&self, id: &FeatureId) -> Option<&GirderIR> {
+        self.girders.get(id)
+    }
+
+    // ── Status ─────────────────────────────────────────────────────────────
+
+    /// Number of Features awaiting recomputation.
+    pub fn dirty_count(&self) -> usize { self.dirty.len() }
+
+    /// Total number of stored Girder Features.
+    pub fn girder_count(&self) -> usize { self.girders.len() }
+}
+
+// ─── Tests ────────────────────────────────────────────────────────────────────
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use cimery_core::{MaterialGrade, SectionType};
+    use cimery_ir::{FeatureId, GirderIR, PscISectionParams, SectionParams};
+    use cimery_kernel::StubKernel;
+
+    fn make_girder(station_start: f64, station_end: f64) -> GirderIR {
+        GirderIR {
+            id: FeatureId::new(),
+            station_start,
+            station_end,
+            offset_from_alignment: 0.0,
+            section_type: SectionType::PscI,
+            section: SectionParams::PscI(PscISectionParams::kds_standard()),
+            count: 1,
+            spacing: 0.0,
+            material: MaterialGrade::C50,
+        }
+    }
+
+    #[test]
+    fn dirty_after_set() {
+        let mut db = IncrementalDb::new(StubKernel);
+        let ir = make_girder(0.0, 40.0);
+        let id = ir.id;
+        db.set_girder(ir);
+        assert_eq!(db.dirty_count(), 1);
+        assert_eq!(db.girder_count(), 1);
+        assert!(db.get_girder(&id).is_some());
+    }
+
+    #[test]
+    fn clean_after_compute() {
+        let mut db = IncrementalDb::new(StubKernel);
+        let ir = make_girder(0.0, 40.0);
+        let id = ir.id;
+        db.set_girder(ir);
+        db.girder_mesh(&id).unwrap();
+        assert_eq!(db.dirty_count(), 0);
+    }
+
+    #[test]
+    fn cache_hit_on_second_call() {
+        let mut db = IncrementalDb::new(StubKernel);
+        let ir = make_girder(0.0, 40.0);
+        let id = ir.id;
+        db.set_girder(ir);
+
+        let m1 = db.girder_mesh(&id).unwrap();
+        let m2 = db.girder_mesh(&id).unwrap(); // must be same Arc
+        assert!(Arc::ptr_eq(&m1, &m2));
+    }
+
+    #[test]
+    fn invalidation_on_update() {
+        let mut db = IncrementalDb::new(StubKernel);
+        let ir = make_girder(0.0, 40.0);
+        let id = ir.id;
+
+        db.set_girder(ir.clone());
+        db.girder_mesh(&id).unwrap();
+        assert_eq!(db.dirty_count(), 0);
+
+        // Update the same girder (longer span)
+        let mut ir2 = ir;
+        ir2.station_end = 50.0;
+        db.set_girder(ir2);
+        assert_eq!(db.dirty_count(), 1); // re-dirtied
+    }
+
+    #[test]
+    fn unknown_id_returns_error() {
+        let mut db = IncrementalDb::new(StubKernel);
+        let missing_id = FeatureId::new();
+        let err = db.girder_mesh(&missing_id);
+        assert!(matches!(err, Err(KernelError::InvalidInput(_))));
+    }
+}