docs(joinir): Phase 232-239 documentation and ExprLowerer refinements

Documentation:
- Move completion reports to docs/archive/reports/
- Add phase232-238 design/inventory documents
- Update joinir-architecture-overview.md
- Add doc-status-policy.md

Code refinements:
- ExprLowerer: condition catalog improvements
- ScopeManager: boundary clarifications
- CarrierInfo: cleanup

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/mir/join_ir/lowering/scope_manager.rs

@@ -146,31 +146,9 @@ impl<'a> ScopeManager for Pattern2ScopeManager<'a> {
             }
         }
 
-        // 4. Promoted LoopBodyLocal → Carrier lookup
-        // If this variable was promoted, try to find its carrier equivalent
-        if self.carrier_info.promoted_loopbodylocals.contains(&name.to_string()) {
-            // Try naming conventions
-            for carrier_name in &[
-                format!("is_{}", name),       // DigitPos pattern
-                format!("is_{}_match", name), // Trim pattern
-            ] {
-                // Check if it's the loop variable (unlikely but possible)
-                if carrier_name == &self.carrier_info.loop_var_name {
-                    if let Some(id) = self.condition_env.get(&self.carrier_info.loop_var_name) {
-                        return Some(id);
-                    }
-                }
-
-                // Otherwise check carriers
-                if let Some(carrier) = self.carrier_info.carriers.iter().find(|c| c.name == *carrier_name) {
-                    if let Some(join_id) = carrier.join_id {
-                        return Some(join_id);
-                    }
-                }
-            }
-        }
-
-        None
+        // 4. Promoted LoopBodyLocal → Carrier lookup（命名規約は CarrierInfo 側に集約）
+        self.carrier_info
+            .resolve_promoted_join_id(name)
     }
 
     fn scope_of(&self, name: &str) -> Option<VarScopeKind> {
@@ -323,4 +301,36 @@ mod tests {
         assert_eq!(scope.lookup("temp"), Some(ValueId(200)));
         assert_eq!(scope.scope_of("temp"), Some(VarScopeKind::LoopBodyLocal));
     }
+
+    #[test]
+    fn test_pattern2_scope_manager_captured() {
+        let mut condition_env = ConditionEnv::new();
+        condition_env.insert("i".to_string(), ValueId(100));
+        condition_env.insert("len".to_string(), ValueId(201));
+
+        let mut captured_env = crate::mir::loop_pattern_detection::function_scope_capture::CapturedEnv::new();
+        captured_env.add_var(CapturedVar {
+            name: "len".to_string(),
+            host_id: ValueId(42),
+            is_immutable: true,
+        });
+
+        let carrier_info = CarrierInfo {
+            loop_var_name: "i".to_string(),
+            loop_var_id: ValueId(1),
+            carriers: vec![],
+            trim_helper: None,
+            promoted_loopbodylocals: vec![],
+        };
+
+        let scope = Pattern2ScopeManager {
+            condition_env: &condition_env,
+            loop_body_local_env: None,
+            captured_env: Some(&captured_env),
+            carrier_info: &carrier_info,
+        };
+
+        assert_eq!(scope.lookup("len"), Some(ValueId(201)));
+        assert_eq!(scope.scope_of("len"), Some(VarScopeKind::Captured));
+    }
 }