Add production build pipeline (#46)

## Summary
- split development dynamic linking from production builds
- add headless processed-asset generation
- add a separate production CI cache and static Bevy/Rust linkage verification
- keep custom debug features enabled for production builds behind a feature gate

Reviewed-on: #46
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

Cargo.toml

@@ -6,8 +6,13 @@ authors = [""]
 
 [workspace]
 
+[features]
+default = ["development", "debug_features"]
+development = ["bevy/dynamic_linking", "bevy/file_watcher"]
+debug_features = ["bevy/free_camera"]
+
 [dependencies]
-bevy = { version = "0.19", features = ["asset_processor", "basis-universal", "dynamic_linking", "free_camera", "file_watcher", "bevy_settings"] }
+bevy = { version = "0.19", features = ["asset_processor", "basis-universal", "bevy_settings"] }
 # Loads the scenes you author in the editor (assets/*.bsn) and builds
 # physics colliders from them. An ordinary dependency; remove it if you
 # stop using authored scenes.
@@ -37,3 +42,9 @@ fixed_math = "0.4.1"
 # Enable a large amount of optimization in the dev profile for dependencies.
 [profile.dev.package."*"]
 opt-level = 3
+
+[profile.production]
+inherits = "release"
+lto = "thin"
+codegen-units = 1
+strip = "symbols"