style: convert CLI status messages to G3Status format

Convert remaining ✅ emoji status messages in g3-cli to use the
consistent G3Status formatting system:

- accumulative.rs: 'autonomous run ... [done]'
- commands.rs /clear: 'clearing session ... [done]'
- commands.rs /readme: 'reloading README ... [done/failed/error]'
- commands.rs /unproject: 'unloading project ... [done]'

This provides a consistent 'g3: action ... [status]' format across
all CLI status messages.

crates/g3-cli/src/accumulative.rs

@@ -183,7 +183,9 @@ pub async fn run_accumulative_mode(
                 match autonomous_result {
                     Ok(Some(_returned_agent)) => {
                         output.print("");
-                        output.print("✅ Autonomous run completed");
+                        use crate::g3_status::G3Status;
+                        G3Status::progress("autonomous run");
+                        G3Status::done();
                     }
                     Ok(None) => {
                         output.print("   (session continuation not saved due to cancellation)");