fix(cli): remove 'stats' from STUB_COMMANDS — it is implemented

/stats was accidentally listed in STUB_COMMANDS (both in the original list
and overlooked in 1e14d59). Since SlashCommand::Stats is fully implemented
with REPL and resume dispatch, it should not be intercepted as unimplemented.

/tokens and /cache alias to Stats and were already working correctly.
/stats now works again in all modes.

rust/crates/rusty-claude-cli/src/main.rs

@@ -7347,7 +7347,6 @@ const STUB_COMMANDS: &[&str] = &[
     "logout",
     "vim",
     "upgrade",
-    "stats",
     "share",
     "feedback",
     "files",
@@ -7385,6 +7384,7 @@ const STUB_COMMANDS: &[&str] = &[
     // Spec entries with no parse arm — produce circular "Did you mean" error
     // without this guard. Adding here routes them to the proper unsupported
     // message and excludes them from REPL completions / help.
+    // NOTE: do NOT add "stats", "tokens", "cache" — they are implemented.
     "allowed-tools",
     "bookmarks",
     "workspace",