Sprint 3 — Must Feature 5종 추가 (상부→하부 순서)

상부 구조물:
- DeckSlabIR + DeckSlabBuilder + 기하학 (직사각형 슬래브 스위프)

연결부:
- BearingIR + BearingBuilder (카탈로그 기반, KDS 기본값 포함)

하부 구조물:
- PierIR + PierBuilder + 기하학 (다주 지원, 코핑 포함)
- AbutmentIR + AbutmentBuilder + 기하학 (흉벽 + 기초 + 날개벽)

core에 BearingType·PierType·ColumnShape·AbutmentType 열거형 추가
kernel: sweep.rs 공유 모듈 (sweep_profile_flat·box·prism·merge)
psc_i.rs → sweep.rs 의존으로 리팩터
GeomKernel trait에 4개 메서드 추가 (상부→하부 문서화 주석)

cargo test 57개 전부 통과

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

cimery/crates/ir/src/lib.rs

@@ -138,6 +138,112 @@ pub struct SteelPlateIParams {
     pub web_thickness:    f64,
 }
 
+// ─── Deck Slab IR ─────────────────────────────────────────────────────────────
+
+/// Fully-resolved Deck Slab (바닥판) specification.
+/// Structural dimensions in mm, alignment in m.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DeckSlabIR {
+    pub id:                FeatureId,
+    pub station_start:     f64,   // m
+    pub station_end:       f64,   // m
+    /// Width left of alignment centreline [mm].
+    pub width_left:        f64,
+    /// Width right of alignment centreline [mm].
+    pub width_right:       f64,
+    /// Slab thickness [mm].
+    pub thickness:         f64,
+    /// Haunch depth over girder top flange [mm].
+    pub haunch_depth:      f64,
+    /// Cross-slope [%]. Positive = right side lower.
+    pub cross_slope:       f64,
+    pub material:          cimery_core::MaterialGrade,
+}
+
+impl DeckSlabIR {
+    pub fn span_m(&self)  -> f64 { self.station_end - self.station_start }
+    pub fn span_mm(&self) -> f64 { self.span_m() * 1_000.0 }
+    pub fn total_width(&self) -> f64 { self.width_left + self.width_right }
+}
+
+// ─── Bearing IR ───────────────────────────────────────────────────────────────
+
+/// Fully-resolved Bearing (받침) specification.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct BearingIR {
+    pub id:                  FeatureId,
+    pub station:             f64,   // m — position along alignment
+    pub bearing_type:        cimery_core::BearingType,
+    /// Dimension along span direction [mm].
+    pub plan_length:         f64,
+    /// Dimension transverse to span [mm].
+    pub plan_width:          f64,
+    pub total_height:        f64,   // mm
+    pub capacity_vertical:   f64,   // kN
+}
+
+// ─── Cap Beam IR ──────────────────────────────────────────────────────────────
+
+/// Pier cap beam (교각 코핑).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CapBeamIR {
+    pub length:            f64,   // mm — total along transverse
+    pub width:             f64,   // mm — along span
+    pub depth:             f64,   // mm — vertical
+    pub cantilever_left:   f64,   // mm — overhang beyond outermost column
+    pub cantilever_right:  f64,
+}
+
+// ─── Pier IR ──────────────────────────────────────────────────────────────────
+
+/// Fully-resolved Pier (교각) specification.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PierIR {
+    pub id:              FeatureId,
+    pub station:         f64,   // m
+    pub skew_angle:      f64,   // degrees — deviation from normal
+    pub pier_type:       cimery_core::PierType,
+    pub column_shape:    cimery_core::ColumnShape,
+    pub column_count:    u32,
+    pub column_spacing:  f64,   // mm — centre-to-centre
+    /// Diameter (circular) or width (rectangular) [mm].
+    pub column_diameter: f64,
+    /// Depth for rectangular section [mm]; ignored for circular.
+    pub column_depth:    f64,
+    pub column_height:   f64,   // mm — footing top to cap beam soffit
+    pub cap_beam:        CapBeamIR,
+    pub material:        cimery_core::MaterialGrade,
+}
+
+// ─── Wing Wall IR ─────────────────────────────────────────────────────────────
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct WingWallIR {
+    pub length:    f64,   // mm — along wing wall axis
+    pub height:    f64,   // mm — at connection with breast wall
+    pub thickness: f64,   // mm
+}
+
+// ─── Abutment IR ──────────────────────────────────────────────────────────────
+
+/// Fully-resolved Abutment (교대) specification.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct AbutmentIR {
+    pub id:                      FeatureId,
+    pub station:                 f64,   // m
+    pub skew_angle:              f64,   // degrees
+    pub abutment_type:           cimery_core::AbutmentType,
+    pub breast_wall_height:      f64,   // mm
+    pub breast_wall_thickness:   f64,   // mm
+    pub breast_wall_width:       f64,   // mm — transverse
+    pub footing_length:          f64,   // mm — along span
+    pub footing_width:           f64,   // mm — transverse
+    pub footing_thickness:       f64,   // mm
+    pub wing_wall_left:          WingWallIR,
+    pub wing_wall_right:         WingWallIR,
+    pub material:                cimery_core::MaterialGrade,
+}
+
 // ─── Tests ────────────────────────────────────────────────────────────────────
 
 #[cfg(test)]