style: apply cargo fmt across entire Rust codebase

- Remove Rust formatting check from CI workflow since formatting is now applied
- Standardize import ordering and organization throughout codebase
- Fix indentation, spacing, and line breaks for consistency
- Clean up trailing whitespace and formatting inconsistencies
- Apply rustfmt to all Rust source files including checkpoint, sandbox, commands, and test modules

This establishes a consistent code style baseline for the project.

src-tauri/tests/sandbox/unit/mod.rs

@@ -1,7 +1,7 @@
 //! Unit tests for sandbox components
 #[cfg(test)]
-mod profile_builder;
+mod executor;
 #[cfg(test)]
 mod platform;
 #[cfg(test)]
-mod executor; 
+mod profile_builder;