fix(cortex-cli): list supported providers in --oss flag help text

Fixes bounty issue #1423

The --oss flag help text now lists ollama as the supported open source
model provider, making it clear to users what options are available.

Author: factorydroid

cortex-cli/src/main.rs

@@ -65,7 +65,7 @@ struct InteractiveArgs {
     #[arg(short, long)]
     model: Option<String>,
 
-    /// Use local open source model provider
+    /// Use local open source model provider (supported: ollama)
     #[arg(long = "oss", default_value_t = false)]
     oss: bool,