fix(engine): 放行固定宿主面与终止面的 pattern 变换

允许 hole_wizard 的 face selector 宿主面及 up_to_surface 的 face reference 终止面参与 pattern 变换，同时保留 mirror 等逐实例拓扑依赖的阻塞，并补充回归测试

backend/engine/cdsl_engine/capabilities.py

@@ -65,28 +65,58 @@ def _has_explicit_host_frame(params: dict[str, Any]) -> bool:
     return isinstance(frame, dict) and all(frame.get(key) is not None for key in ("origin_mm", "x_dir", "normal"))
 
 
+def _is_host_face_source(source: FeaturePlanNode) -> bool:
+    """Whether a ``face`` selector on the source is a fixed host face.
+
+    A patterned hole keeps its host face: the instance positions travel with
+    the pattern (``_translated_node`` shifts ``positions``) while the face
+    itself is resolved unchanged, so the face selector can stay untouched
+    (issue #6).  A face selector on anything else (for example a fillet
+    selecting a face) would need per-instance edge geometry and must stay
+    blocked.
+    """
+    return source.atomic_id in _HOLE_ATOMICS or (
+        isinstance(source.params.get("host_face"), dict)
+        and source.params.get("host_face", {}).get("kind") == "face"
+    )
+
+
 def pattern_transform_blocker(source: FeaturePlanNode) -> str | None:
     """Return the selector dependency that cannot be transformed exactly.
 
     Selectors fully captured by explicit coordinate data (a revolve axis with
     origin/direction, or a host face with a complete world frame) are
     transformed together with each patterned instance and are not blockers.
-    Any remaining topology selector and selector-dependent extent stays
-    blocked until its geometry transform contract is implemented.
+    A patterned hole's host face and an up_to_surface extrusion's target face
+    are *fixed* body faces rather than instance geometry: positions and
+    profiles travel with the instance while the face itself is resolved
+    unchanged (issue #6).  Selectors that must follow the instance but cannot
+    be translated (edges, vertices, …) stay blocked until their geometry
+    transform contract is implemented.
     """
     for selector in source.selectors or ():
         if selector.get("kind") == "axis" and _has_explicit_axis(source.params.get("axis")):
             # The axis is coordinate data; _translated_node shifts its origin.
             continue
-        if selector.get("kind") == "face" and _has_explicit_host_frame(source.params):
-            # The host face carries a complete world frame; positions stay local.
+        if selector.get("kind") == "face" and _is_host_face_source(source):
+            # 孔宿主面：主体上的固定面，不随实例平移；实例位置由 positions
+            # 平移决定（_translated_node），selector 原样保留即可正确 resolve。
             continue
         return "feature selector"
     host = source.params.get("host_face")
     if host is not None and not _has_explicit_host_frame(source.params):
-        return "host face selector"
+        # 无 frame 的孔：宿主面以 face selector 形式给出（host_face 自身或
+        # selectors 列表）→ 上面的 face 分支已放行；其它形态（无 frame 也
+        # 非 face selector）仍阻塞。
+        if not (isinstance(host, dict) and host.get("kind") == "face"):
+            return "host face selector"
     end_condition = source.params.get("end_condition") or {}
     if isinstance(end_condition, dict) and isinstance(end_condition.get("reference"), dict):
+        # up_to_surface / offset_from_surface 的终止面是主体上的固定面：
+        # 不随实例平移，reference 原样保留即可正确 resolve（#5 裁剪已支持
+        # 非均匀相交）。顶点/主体目标无法构造"固定终止面"，仍显式阻塞。
+        if end_condition["reference"].get("kind") == "face":
+            return None
         return "extent target selector"
     return None