Introduces a _BlurPixels property and related parameters to BlendinShader and LitParticles shaders, enabling blurred shadowcaster sampling. Updates Shadowcaster.cginc to support blurred texture sampling using tex2Dgrad when blur is enabled. Also adjusts light intensity calculation in LightStrength.hlsl to remove NdotL multiplication for consistency with new shadow handling.
Replaces the use of world-to-local matrices for shadowcaster planes with explicit plane origin, basis, and normal vectors in both C# and shader code. Updates property setting in ShadowcasterUpdater and its editor preview, and rewrites the shadow sampling function in the shader include to use the new basis. Adjusts all affected shaders to use the new properties and sampling function for improved clarity and flexibility.
Introduces shadowcaster support by adding shadow map index fields to light data, updating PlayerPositionsToShader and LightdataStorage to handle shadow map indices, and extending the shader and its includes to sample shadowcaster planes. Adds ShadowcasterUpdater script and editor preview for updating world-to-local matrices, and updates relevant arrays and property handling throughout the codebase. Also adds a sample plane mesh for shadowcasting.
