# RetrieX Patch 9.0c - PromptBuilder Output Priority and Fallback Escalation YAML-only

Scope:
- Converts the next small PromptBuilderConfig rule group to YAML-only.
- Requires Patch 9.0b as the previous state.

Changed:
- src/Config/PromptBuilderConfig.php

YAML-only paths:
- output_priority.rules
- output_priority.technical_rules
- sections.fallback_escalation_label
- fallback_escalation.state_line_template
- fallback_escalation.base_rules
- fallback_escalation.without_shop_check_rules

Optional path behavior:
- fallback_escalation.states.<state> remains optional and returns an empty list when a specific state is not configured.
- This is implemented without using the old getStringList(..., []) PHP fallback accessor.

Not changed:
- response_format.*
- language.rules
- fact_grounding.*
- role_guard.*
- measurement_evidence_guard.*
- Retrieval, Commerce, ShopService, AgentRunner, SSE/frontend

Validation performed in the patch workspace:
- php -n -l src/Config/PromptBuilderConfig.php

Recommended checks after applying:
- php bin/console cache:clear
- php bin/console mto:agent:config:validate
- php bin/console mto:agent:config:audit-source --details
- php bin/console mto:agent:regression:test
