feat: add GPT/Codex execution discipline guidance for tool persistence (#5414)

Adds OPENAI_MODEL_EXECUTION_GUIDANCE — XML-tagged behavioral guidance
injected for GPT and Codex models alongside the existing tool-use
enforcement. Targets four specific failure modes:

- <tool_persistence>: retry on empty/partial results instead of giving up
- <prerequisite_checks>: do discovery/lookup before jumping to final action
- <verification>: check correctness/grounding/formatting before finalizing
- <missing_context>: use lookup tools instead of hallucinating

Follows the same injection pattern as GOOGLE_MODEL_OPERATIONAL_GUIDANCE
for Gemini/Gemma models. Inspired by OpenClaw PR #38953 and OpenAI's
GPT-5.4 prompting guide patterns.

run_agent.py

@@ -90,7 +90,7 @@ from agent.model_metadata import (
 from agent.context_compressor import ContextCompressor
 from agent.subdirectory_hints import SubdirectoryHintTracker
 from agent.prompt_caching import apply_anthropic_cache_control
-from agent.prompt_builder import build_skills_system_prompt, build_context_files_prompt, load_soul_md, TOOL_USE_ENFORCEMENT_GUIDANCE, TOOL_USE_ENFORCEMENT_MODELS, DEVELOPER_ROLE_MODELS, GOOGLE_MODEL_OPERATIONAL_GUIDANCE
+from agent.prompt_builder import build_skills_system_prompt, build_context_files_prompt, load_soul_md, TOOL_USE_ENFORCEMENT_GUIDANCE, TOOL_USE_ENFORCEMENT_MODELS, DEVELOPER_ROLE_MODELS, GOOGLE_MODEL_OPERATIONAL_GUIDANCE, OPENAI_MODEL_EXECUTION_GUIDANCE
 from agent.usage_pricing import estimate_usage_cost, normalize_usage
 from agent.display import (
     KawaiiSpinner, build_tool_preview as _build_tool_preview,
@@ -2791,11 +2791,15 @@ class AIAgent:
                 _inject = any(p in model_lower for p in TOOL_USE_ENFORCEMENT_MODELS)
             if _inject:
                 prompt_parts.append(TOOL_USE_ENFORCEMENT_GUIDANCE)
+                _model_lower = (self.model or "").lower()
                 # Google model operational guidance (conciseness, absolute
                 # paths, parallel tool calls, verify-before-edit, etc.)
-                _model_lower = (self.model or "").lower()
                 if "gemini" in _model_lower or "gemma" in _model_lower:
                     prompt_parts.append(GOOGLE_MODEL_OPERATIONAL_GUIDANCE)
+                # OpenAI GPT/Codex execution discipline (tool persistence,
+                # prerequisite checks, verification, anti-hallucination).
+                if "gpt" in _model_lower or "codex" in _model_lower:
+                    prompt_parts.append(OPENAI_MODEL_EXECUTION_GUIDANCE)
 
         # so it can refer the user to them rather than reinventing answers.