Refinery agents do not follow REVIEW.md from reviewed branches

[IamCoder18]

PR #3183 added support for repository-level REVIEW.md guidance to Kilo web code reviews, allowing repositories to define custom review policies that replace the built-in "WHAT TO REVIEW" section. However, Gas Town Refinery agents do not follow REVIEW.md despite performing similar code review tasks in a different context.

Current behavior:

• Refinery system prompt contains hardcoded review guidance (correctness, style, test coverage, security, build artifacts)
• No check for or use of REVIEW.md in the workspace
• Review policies cannot be customized per repository for Gas Town operations

Expected behavior:

• Refinery agents should check for REVIEW.md in the workspace root at the start of code review
• When present, follow its guidance for what to flag, severity calibration, skip rules, and summary format
• When absent, fall back to the default hardcoded guidance
• Apply to both buildRefinerySystemPrompt() (direct merge mode) and buildPRReviewPrompt() (PR review mode)

Impact:

• Gas Town users cannot enforce repository-specific review policies that web users can
• Inconsistent review behavior between web and Gas Town code review systems
• Teams using REVIEW.md for CI/bot review workflows miss out on the same customization in Gas Town