fix(gui): Skip empty strings in selectable to prevent ImGui ID assertion

Empty strings in bias_profiles.keys() and personas.keys() caused
imgui.selectable() to fail with 'Cannot have an empty ID at root of
window' assertion error. Added guards to skip empty names.

.opencode/agents/tier4-qa.md

@@ -1,7 +1,7 @@
----
+---
 description: Stateless Tier 4 QA Agent for error analysis and diagnostics
 mode: subagent
-model: MiniMax-M2.5
+model: 	minimax-coding-plan/MiniMax-M2.7
 temperature: 0.2
 permission:
   edit: deny
@@ -119,4 +119,4 @@ If you cannot analyze the error:
 - Do NOT read full large files - use skeleton tools first
 - DO NOT SKIP A TEST IN PYTEST JUST BECAUSE ITS BROKEN AND HAS NO TRIVIAL SOLUTION OR FIX.
 - DO NOT SIMPLIFY A TEST JUST BECAUSE IT HAS NO TRIVIAL SOLUTION TO FIX.
-- DO NOT CREATE MOCK PATCHES TO PSEUDO API CALLS OR HOOKS BECAUSE THE APP SOURCE WAS CHANGED. ADAPT TESTS PROPERLY.
+- DO NOT CREATE MOCK PATCHES TO PSEUDO API CALLS OR HOOKS BECAUSE THE APP SOURCE WAS CHANGED. ADAPT TESTS PROPERLY.