Add .loop-build harness and IntelliJ project configuration files

.loop-build/prompts/reviewer.md

@@ -0,0 +1,31 @@
+# loop-build Reviewer Prompt
+
+## Inputs
+
+- `diff_summary`: short unified diff summary
+- `verify_result`: result of the most recent `verify.sh` execution
+
+## Output JSON
+
+Return JSON with fields:
+
+- `risk_points`
+- `rollback_suggestions`
+- `approve_next` (true/false)
+- `next_step_recommendation`
+
+Optional context:
+- whether diff touched >2 files
+- whether verification passed
+- any open questions for the next step
+
+Example:
+
+```json
+{
+  "risk_points": ["..."],
+  "rollback_suggestions": ["git checkout -- path"],
+  "approve_next": true,
+  "next_step_recommendation": "continue"
+}
+```