feat: update version to 0.6.9 and add packaging for Linux and BSD

- Bump version from 0.6.8 to 0.6.9 in Cargo.toml and Cargo.lock.
- Enhance GitHub Actions workflow to build and publish .deb, .rpm, and Snap packages.
- Implement AUR publishing for both dcr and dcr-bin packages.
- Add support for workspace-only projects in the build system.
- Introduce new `workspace` flag for build and run commands.
- Create snapcraft.yaml for Snap package configuration.
- Update build.rs and related files to handle workspace members and inheritance.
- Modify config handling to support optional package and build configurations.

src/core/workspace.rs

@@ -26,6 +26,7 @@ pub struct WorkspaceMember {
     pub name: String,
     pub path: PathBuf,
     pub deps: Vec<String>,
+    pub main: bool,
 }
 
 #[derive(Debug, Clone)]
@@ -33,6 +34,15 @@ pub struct Workspace {
     pub members: Vec<WorkspaceMember>,
 }
 
+impl Workspace {
+    pub fn main_member(&self) -> Option<&WorkspaceMember> {
+        self.members
+            .iter()
+            .find(|m| m.main)
+            .or_else(|| self.members.first())
+    }
+}
+
 pub fn parse_workspace(
     config: &Config,
     profile: &str,
@@ -85,6 +95,7 @@ pub fn parse_workspace(
             name: name.to_string(),
             path,
             deps,
+            main: tbl.get("main").and_then(|v| v.as_bool()).unwrap_or(false),
         });
     }