Add enhanced rollback functionality and comprehensive documentation

- Implement two-phase rollback system inspired by apt-tx project
- Add package state tracking (newly_installed, upgraded, previously_installed)
- Enhance both core and advanced transaction APIs with rollback methods
- Add comprehensive rollback documentation in docs/rollback.md
- Create rollback_demo.rs example demonstrating functionality
- Update README with detailed crate usage instructions
- Add rollback features to feature flags documentation
- Fix import issues in advanced crate modules
- Add get_installed_packages method to AptCommands
- Include both crates.io and git installation options in README

apt-dnf-bridge/Cargo.toml

@@ -12,6 +12,7 @@ categories.workspace = true
 apt-dnf-bridge-core = { path = "../apt-dnf-bridge-core" }
 apt-dnf-bridge-advanced = { path = "../apt-dnf-bridge-advanced", optional = true }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
+anyhow = { workspace = true }
 
 [features]
 default = []  # Core-only by default
@@ -35,3 +36,7 @@ path = "../examples/atomicity_notes.rs"
 [[example]]
 name = "backend_selection"
 path = "../examples/backend_selection.rs"
+
+[[example]]
+name = "rollback_demo"
+path = "../examples/rollback_demo.rs"

apt-dnf-bridge/src/lib.rs

@@ -45,3 +45,4 @@ pub use apt_dnf_bridge_core::*;
 // Conditionally expose advanced features
 #[cfg(feature = "advanced")]
 pub use apt_dnf_bridge_advanced::*;
+