Implement Phase 4: Advanced dependency resolution features

- Add dependency_resolver module with advanced conflict detection
- Implement DependencyResolver with circular dependency detection
- Add package metadata structures (DebPackageMetadata, DependencyConstraint)
- Integrate dependency resolution into lib.rs exports
- Support for dependency tree resolution and validation
- Conflict detection with severity levels (Critical, Warning, Info)
- Known system conflict detection (mail servers, display managers, init systems)
- Generate comprehensive dependency resolution reports

src/dependency_resolver.rs

@@ -8,7 +8,19 @@ use tracing::{info, warn, debug};
 use serde::{Serialize, Deserialize};
 
 use crate::error::{AptOstreeError, AptOstreeResult};
-use crate::apt_ostree_integration::DebPackageMetadata;
+
+/// DEB package metadata for dependency resolution
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DebPackageMetadata {
+    pub name: String,
+    pub version: String,
+    pub architecture: String,
+    pub depends: Vec<String>,
+    pub conflicts: Vec<String>,
+    pub provides: Vec<String>,
+    pub breaks: Vec<String>,
+    pub replaces: Vec<String>,
+}
 
 /// Dependency relationship types
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]

src/lib.rs

@@ -4,6 +4,9 @@
 
 pub mod apt_compat;
 pub mod error;
+pub mod dependency_resolver;
+pub mod ostree_integration;
 
 pub use apt_compat::AptManager;
-pub use error::{AptOstreeError, AptOstreeResult}; 
+pub use error::{AptOstreeError, AptOstreeResult}; 
+pub use dependency_resolver::{DependencyResolver, DependencyConstraint, DependencyRelation, DependencyGraph, ResolvedDependencies};