fix(chat): hydrate restored session model on boot

static/boot.js

@@ -1654,6 +1654,12 @@ function applyBotName(){
         return;
       }
       await loadSession(saved);
+      // Hard refresh starts from the static HTML model list. Hydrate the live
+      // catalog after the saved session is known, then re-apply that session's
+      // model before S._bootReady lets syncModelChip reveal the composer label.
+      // Otherwise the chip can display the static default (e.g. GPT-5.4 Mini)
+      // even though S.session already points at the Codex/current model.
+      if(S.session) await _startBootModelDropdown();
       // If the restored session has no messages it is an ephemeral scratch pad —
       // treat the page as a fresh start rather than resuming a blank conversation.
       // loadSession() already ran, so loadDir() has populated the workspace file tree.

tests/test_new_chat_default_model_frontend.py

@@ -56,6 +56,18 @@ def test_boot_model_hydration_prefers_active_session_over_persisted_model():
     )
 
 
+def test_hard_refresh_hydrates_saved_session_model_before_revealing_model_chip():
+    boot_js = Path("static/boot.js").read_text(encoding="utf-8")
+    load_marker = "await loadSession(saved);"
+    assert load_marker in boot_js
+    saved_restore = boot_js[boot_js.index(load_marker) : boot_js.index("await checkInflightOnBoot(saved);return;", boot_js.index(load_marker))]
+    assert "await _startBootModelDropdown();" in saved_restore
+    assert saved_restore.index("await _startBootModelDropdown();") > saved_restore.index(load_marker)
+    assert saved_restore.index("await _startBootModelDropdown();") < saved_restore.index("S._bootReady=true;"), (
+        "hard refresh must hydrate/re-apply the active session model before S._bootReady lets syncModelChip display stale static HTML defaults"
+    )
+
+
 def test_new_chat_does_not_send_stale_dropdown_model_when_session_has_default_model():
     assert "model:S.session.model||$('modelSelect').value" in MESSAGES_JS
     assert "model_provider:S.session.model_provider||null" in MESSAGES_JS