Fix: CLI generate command works with single invocation

The remove_env_flags function was incorrectly returning index 0 when no --env
flag was present, causing it to mistakenly skip the first argument
(program name) and shift all arguments incorrectly.

This required users to specify 'generate' twice to make the CLI work.

Fix by checking if --env was actually found (env_idx > 0) before removing
any arguments from the list.

AGENTS.md

@@ -0,0 +1,10 @@
+# Issue Management
+- Use Gitea REST API to close issues when fixing them:
+  ```bash
+  curl -X PATCH https://gitea.rowanbrook.net/api/v1/repos/jakob/rusty-petroleum/issues/{issue_number} \
+    -H "Content-Type: application/json" \
+    -H "Authorization: Bearer YOUR_TOKEN" \
+    -d '{"state": "closed"}'
+  ```
+- Or suggest closing issues on Gitea web UI when automatic closing via API is not configured
+

src/main.rs

@@ -263,6 +263,9 @@ fn parse_env_flag(args: &[String]) -> (Env, usize) {
 /// command without affecting positional argument parsing.
 fn remove_env_flags(args: &[String]) -> Vec<String> {
     let (_, env_idx) = parse_env_flag(args);
+    if env_idx == 0 {
+        return args.to_vec();
+    }
     let mut result = Vec::with_capacity(args.len());
     
     for (i, arg) in args.iter().enumerate() {