feat: make it possible to set disable_response_storage = true in config.toml (#714)

https://github.com/openai/codex/pull/642 introduced support for the
`--disable-response-storage` flag, but if you are a ZDR customer, it is
tedious to set this every time, so this PR makes it possible to set this
once in `config.toml` and be done with it.

Incidentally, this tidies things up such that now `init_codex()` takes
only one parameter: `Config`.

codex-rs/repl/src/lib.rs

@@ -81,6 +81,11 @@ pub async fn run_main(cli: Cli) -> anyhow::Result<()> {
         model: cli.model.clone(),
         approval_policy: cli.approval_policy.map(Into::into),
         sandbox_policy: cli.sandbox_policy.map(Into::into),
+        disable_response_storage: if cli.disable_response_storage {
+            Some(true)
+        } else {
+            None
+        },
     };
     let config = Config::load_with_overrides(overrides)?;
 
@@ -104,7 +109,7 @@ async fn codex_main(cli: Cli, cfg: Config, ctrl_c: Arc<Notify>) -> anyhow::Resul
             instructions: cfg.instructions,
             approval_policy: cfg.approval_policy,
             sandbox_policy: cfg.sandbox_policy,
-            disable_response_storage: cli.disable_response_storage,
+            disable_response_storage: cfg.disable_response_storage,
         },
     };