feat: Implement background shader and visual effects

- Added a new WGSL shader for background rendering with volumetric fog effects.
- Created components for game entities including Circle, Velocity, Explosion, and ChainReaction.
- Introduced game state management with GameState enum and LevelState resource.
- Implemented event system for explosion requests and circle destruction notifications.
- Developed plugins for game logic, input handling, movement, reactions, scoring, and UI.
- Configured game settings through GameConfig resource with adjustable parameters.
- Enhanced UI with configuration options and game over screens.
- Integrated spatial grid for efficient collision detection and explosion handling.

Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "chain-reaction"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+rand = "0.9.2"
+
+[dependencies.bevy]
+version = "0.17.3"
+default-features = true
+
+[profile.dev]
+opt-level = 1
+
+# Enable a large amount of optimization in the dev profile for dependencies.
+[profile.dev.package."*"]
+opt-level = 3
+
+# Enable more optimization in the release profile at the cost of compile time.
+[profile.release]
+# Compile the entire crate as one unit.
+# Slows compile times, marginal improvements.
+codegen-units = 1
+# Do a second optimization pass over the entire program, including dependencies.
+# Slows compile times, marginal improvements.
+lto = "thin"
+
+# Optimize for size in the wasm-release profile to reduce load times and bandwidth usage on web.
+[profile.wasm-release]
+# Default to release profile values.
+inherits = "release"
+# Optimize with size in mind (also try "z", sometimes it is better).
+# Slightly slows compile times, great improvements to file size and runtime performance.
+opt-level = "s"
+# Strip all debugging information from the binary to slightly reduce file size.
+strip = "debuginfo"