feat: Implement build state tracking and interactive package specification creation

- Added StateTracker to manage build steps and allow resuming interrupted builds.
- Updated post_extract function to utilize StateTracker for patch and command execution.
- Introduced makefile.rs to handle building and installing packages via Makefile.
- Created interactive.rs for an interactive package specification creator with SHA256 computation for source URLs.
- Enhanced checksum verification to support multiple algorithms (SHA256, SHA512, MD5).
- Added example configuration files in contrib for system-wide and user-level Depot configurations.
- Updated tests to cover new functionality and ensure correctness of state tracking and interactive creation.

src/builder/bin.rs

@@ -40,3 +40,71 @@ pub fn build(
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::package::{Build, BuildFlags, BuildType, Dependencies, PackageInfo};
+    use tempfile::tempdir;
+    use std::fs;
+    use std::os::unix::fs as unix_fs;
+
+    fn mk_spec(name: &str, version: &str) -> PackageSpec {
+        PackageSpec {
+            package: PackageInfo {
+                name: name.into(),
+                version: version.into(),
+                revision: 1,
+                description: "d".into(),
+                homepage: "h".into(),
+                license: "MIT".into(),
+            },
+            packages: Vec::new(),
+            alternatives: Default::default(),
+            manual_sources: Vec::new(),
+            source: vec![crate::package::Source {
+                url: "h".into(),
+                sha256: "s".into(),
+                extract_dir: "e".into(),
+                patches: Vec::new(),
+                post_extract: Vec::new(),
+            }],
+            build: Build {
+                build_type: BuildType::Bin,
+                flags: BuildFlags::default(),
+            },
+            dependencies: Dependencies::default(),
+            spec_dir: std::path::PathBuf::from("."),
+        }
+    }
+
+    #[test]
+    fn test_bin_build_copies_files_and_symlinks() -> Result<()> {
+        let tmp_src = tempdir()?;
+        let tmp_dest = tempdir()?;
+        let src = tmp_src.path();
+        let dest = tmp_dest.path();
+
+        // Create a directory and files
+        fs::create_dir_all(src.join("usr/bin"))?;
+        fs::write(src.join("usr/bin/hello"), b"hi")?;
+
+        // Create a symlink
+        let target = src.join("usr/lib/libdummy.so");
+        fs::create_dir_all(target.parent().unwrap())?;
+        fs::write(&target, b"lib")?;
+        unix_fs::symlink(&target, src.join("usr/lib/libdummy.so.link"))?;
+
+        let spec = mk_spec("bin-test", "1.0");
+        build(&spec, src, dest, None)?;
+
+        // Check copied file
+        assert!(dest.join("usr/bin/hello").exists());
+
+        // Check symlink target exists at dest
+        let link_path = dest.join("usr/lib/libdummy.so.link");
+        assert!(link_path.exists());
+
+        Ok(())
+    }
+}