feat: Enhance play notebook and camera module with new functionalities

- Updated play notebook with additional imports and new functions for point triangulation and undistortion.
- Introduced `triangulate_one_point_from_multiple_views_linear` and `triangulate_points_from_multiple_views_linear` for batch triangulation of points.
- Added `triangle_from_cluster` function to facilitate triangulation from detection clusters.
- Enhanced `CameraParams` and `Detection` dataclasses with a projection matrix property for improved usability.
- Cleaned up imports and execution counts in the notebook for better organization.

.vscode/settings.json

@@ -1,7 +1,4 @@
 {
     "python.analysis.typeCheckingMode": "basic",
     "python.analysis.autoImportCompletions": true,
-    "cSpell.words": [
-        "triu"
-    ]
 }

app/camera/__init__.py

@@ -13,7 +13,7 @@ CameraID: TypeAlias = str  # pylint: disable=invalid-name
 
 
 @jaxtyped(typechecker=beartype)
-@dataclass
+@dataclass(frozen=True)
 class CameraParams:
     """
     Camera parameters: intrinsic matrix, extrinsic matrix, and distortion coefficients
@@ -42,9 +42,23 @@ class CameraParams:
     The size of image plane (width, height)
     """
 
+    @property
+    def projection_matrix(self) -> Num[Array, "3 4"]:
+        """
+        Returns the 3x4 projection matrix K @ [R|t].
+
+        The result is cached on first access. (lazy evaluation)
+        """
+        pm = getattr(self, "_proj", None)
+        if pm is None:
+            pm = self.K @ self.Rt[:3, :]
+            # object.__setattr__ bypasses the frozen‐dataclass blocker
+            object.__setattr__(self, "_proj", pm)
+        return pm
+
 
 @jaxtyped(typechecker=beartype)
-@dataclass
+@dataclass(frozen=True)
 class Camera:
     """
     a description of a camera
@@ -61,7 +75,7 @@ class Camera:
 
 
 @jaxtyped(typechecker=beartype)
-@dataclass
+@dataclass(frozen=True)
 class Detection:
     """
     One detection from a camera