feat: Add weevil uninstall command

Adds `weevil uninstall` with three modes of operation:
- Full uninstall removes the entire .weevil directory
- --dry-run enumerates managed components and their sizes
- --only N removes specific components by index

Acknowledges system-installed dependencies (Android SDK, Gradle)
in dry-run output so users know what will and won't be touched.

src/main.rs

@@ -42,6 +42,17 @@ enum Commands {
         path: Option<String>,
     },
     
+    /// Remove Weevil-installed SDKs and dependencies
+    Uninstall {
+        /// Show what would be removed without actually removing anything
+        #[arg(long)]
+        dry_run: bool,
+        
+        /// Remove only specific items by number (use --dry-run first to see the list)
+        #[arg(long, value_name = "NUM", num_args = 1..)]
+        only: Option<Vec<usize>>,
+    },
+    
     /// Upgrade an existing project to the latest generator version
     Upgrade {
         /// Path to the project directory
@@ -114,6 +125,9 @@ fn main() -> Result<()> {
         Commands::Setup { path } => {
             commands::setup::setup_environment(path.as_deref())
         }
+        Commands::Uninstall { dry_run, only } => {
+            commands::uninstall::uninstall_dependencies(dry_run, only)
+        }
         Commands::Upgrade { path } => {
             commands::upgrade::upgrade_project(&path)
         }