fix(cli): add dry run for agent copy

src/cortex-cli/src/agent_cmd/cli.rs

@@ -184,6 +184,10 @@ pub struct CopyArgs {
     /// Force overwrite if destination agent already exists.
     #[arg(short, long)]
     pub force: bool,
+
+    /// Show what would be copied without writing the destination file.
+    #[arg(long = "dry-run")]
+    pub dry_run: bool,
 }
 
 /// Arguments for export command.

src/cortex-cli/src/agent_cmd/handlers/copy.rs

@@ -31,7 +31,7 @@ pub async fn run_copy(args: CopyArgs) -> Result<()> {
 
     // Check if destination already exists
     let dest_exists = agents.iter().any(|a| a.name == args.destination);
-    if dest_exists && !args.force {
+    if dest_exists && !args.force && !args.dry_run {
         bail!(
             "Agent '{}' already exists. Use --force to overwrite.",
             args.destination
@@ -40,10 +40,41 @@ pub async fn run_copy(args: CopyArgs) -> Result<()> {
 
     // Get the agents directory
     let agents_dir = get_agents_dir()?;
-    std::fs::create_dir_all(&agents_dir)?;
-
     let dest_file = agents_dir.join(format!("{}.md", args.destination));
 
+    if args.dry_run {
+        println!(
+            "Would copy agent '{}' to '{}'",
+            args.source, args.destination
+        );
+        println!(
+            "   Source: {}",
+            source_agent
+                .path
+                .as_ref()
+                .map(|path| path.display().to_string())
+                .unwrap_or_else(|| "builtin".to_string())
+        );
+        println!("   Destination: {}", dest_file.display());
+        println!(
+            "   Destination exists: {}",
+            if dest_exists { "yes" } else { "no" }
+        );
+        println!(
+            "   Force required: {}",
+            if dest_exists && !args.force {
+                "yes"
+            } else {
+                "no"
+            }
+        );
+        println!();
+        println!("No files written (dry run).");
+        return Ok(());
+    }
+
+    std::fs::create_dir_all(&agents_dir)?;
+
     // Generate the agent content
     let content = if source_agent.native {
         // For built-in agents, create a new file from scratch

src/cortex-cli/src/agent_cmd/tests.rs

@@ -3,10 +3,9 @@
 #[cfg(test)]
 mod tests {
     use crate::agent_cmd::cli::{CopyArgs, ExportArgs};
-    use crate::agent_cmd::loader::{
-        load_builtin_agents, parse_frontmatter, read_file_with_encoding,
-    };
+    use crate::agent_cmd::loader::{load_builtin_agents, parse_frontmatter};
     use crate::agent_cmd::types::AgentMode;
+    use crate::utils::file::read_file_with_encoding;
 
     #[test]
     fn test_read_file_with_utf8() {
@@ -89,9 +88,23 @@ mod tests {
             source: "build".to_string(),
             destination: "my-build".to_string(),
             force: false,
+            dry_run: false,
         };
         assert_eq!(args.source, "build");
         assert_eq!(args.destination, "my-build");
+        assert!(!args.dry_run);
+    }
+
+    #[test]
+    fn test_copy_args_dry_run() {
+        let args = CopyArgs {
+            source: "build".to_string(),
+            destination: "my-build".to_string(),
+            force: false,
+            dry_run: true,
+        };
+
+        assert!(args.dry_run);
     }
 
     #[test]