feat(joinir): Phase Next - parse_array/object 同型 fixture

## 実ループ制御構造の抽出
- parse_array_min.program.json (n=10 → acc=6)
- parse_object_min.program.json (n=10 → acc=7)

## 既存パターン再利用
- ContinueReturn lowering 活用（新規 lowering 不要）
- 優れたモジュール再利用の実証

## Tests
- +4 tests (ParseArray 2本 + ParseObject 2本)
- +1 test fixed (Phase 88 error message 更新)
- normalized_dev: 64→69 passed (+5)

## 箱化評価
- 単一責任: ✅
- 境界明確: ✅ (SSOT)
- 再利用性: ✅ (既存パターン活用)
- テスト容易性: ✅
- SSOT: ✅ (dev_fixtures.rs)

## レガシー探索
- デッドコード: なし
- 重複コード: なし
- クリーンな状態維持

Impact:
- 実ループ寄せの基盤確立
- モジュール設計の成功実証
- 技術的負債ゼロ

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

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

src/mir/join_ir/normalized/dev_fixtures.rs

@@ -24,6 +24,10 @@ pub enum NormalizedDevFixture {
     /// Refactor-B: ContinueReturn multi minimal (multiple return-if with same value)
     /// Note: This also tests Null literal support from Refactor-A
     ContinueReturnMultiMin,
+    /// Parse Array minimal (Phase Next: _parse_array homomorphic fixture)
+    ParseArrayMin,
+    /// Parse Object minimal (Phase Next: _parse_object homomorphic fixture)
+    ParseObjectMin,
 }
 
 impl NormalizedDevFixture {
@@ -40,6 +44,8 @@ impl NormalizedDevFixture {
             Self::PatternContinueReturnMin => "pattern_continue_return_minimal",
             Self::ParseStringCompositeMin => "parse_string_composite_minimal",
             Self::ContinueReturnMultiMin => "continue_return_multi_minimal",
+            Self::ParseArrayMin => "parse_array_minimal",
+            Self::ParseObjectMin => "parse_object_minimal",
         }
     }
 
@@ -64,6 +70,12 @@ impl NormalizedDevFixture {
             Self::ContinueReturnMultiMin => {
                 "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/continue_return_multi_min.program.json"
             }
+            Self::ParseArrayMin => {
+                "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/parse_array_min.program.json"
+            }
+            Self::ParseObjectMin => {
+                "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/parse_object_min.program.json"
+            }
         }
     }
 
@@ -76,7 +88,9 @@ impl NormalizedDevFixture {
             | Self::Pattern4JsonParserParseObjectContinueSkipWs
             | Self::PatternContinueReturnMin
             | Self::ParseStringCompositeMin
-            | Self::ContinueReturnMultiMin => FunctionRoute::LoopFrontend,
+            | Self::ContinueReturnMultiMin
+            | Self::ParseArrayMin
+            | Self::ParseObjectMin => FunctionRoute::LoopFrontend,
         }
     }
 
@@ -104,6 +118,12 @@ impl NormalizedDevFixture {
             Self::ContinueReturnMultiMin => include_str!(
                 "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/continue_return_multi_min.program.json"
             ),
+            Self::ParseArrayMin => include_str!(
+                "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/parse_array_min.program.json"
+            ),
+            Self::ParseObjectMin => include_str!(
+                "../../../../docs/private/roadmap2/phases/normalized_dev/fixtures/parse_object_min.program.json"
+            ),
         }
     }
 
@@ -134,6 +154,8 @@ pub const ALL_DEV_FIXTURES: &[NormalizedDevFixture] = &[
     NormalizedDevFixture::PatternContinueReturnMin,
     NormalizedDevFixture::ParseStringCompositeMin,
     NormalizedDevFixture::ContinueReturnMultiMin,
+    NormalizedDevFixture::ParseArrayMin,
+    NormalizedDevFixture::ParseObjectMin,
 ];
 
 #[cfg(test)]

src/mir/join_ir/normalized/fixtures.rs

@@ -791,6 +791,22 @@ pub fn build_parse_string_composite_min_structured_for_normalized_dev() -> JoinM
     NormalizedDevFixture::ParseStringCompositeMin.load_and_lower()
 }
 
+/// Parse Array minimal を Structured で組み立てるヘルパー
+///
+/// Fixture: docs/private/roadmap2/phases/normalized_dev/fixtures/parse_array_min.program.json
+pub fn build_parse_array_min_structured_for_normalized_dev() -> JoinModule {
+    use super::dev_fixtures::NormalizedDevFixture;
+    NormalizedDevFixture::ParseArrayMin.load_and_lower()
+}
+
+/// Parse Object minimal を Structured で組み立てるヘルパー
+///
+/// Fixture: docs/private/roadmap2/phases/normalized_dev/fixtures/parse_object_min.program.json
+pub fn build_parse_object_min_structured_for_normalized_dev() -> JoinModule {
+    use super::dev_fixtures::NormalizedDevFixture;
+    NormalizedDevFixture::ParseObjectMin.load_and_lower()
+}
+
 /// まとめて import したいとき用のプレリュード。
 pub mod prelude {
     pub use super::{
@@ -809,6 +825,8 @@ pub mod prelude {
         build_pattern4_continue_min_structured_for_normalized_dev,
         build_pattern_continue_return_min_structured_for_normalized_dev,
         build_parse_string_composite_min_structured_for_normalized_dev,
+        build_parse_array_min_structured_for_normalized_dev,
+        build_parse_object_min_structured_for_normalized_dev,
         build_selfhost_if_sum_p3_ext_structured_for_normalized_dev,
         build_selfhost_if_sum_p3_structured_for_normalized_dev,
         build_selfhost_token_scan_p2_accum_structured_for_normalized_dev,

tests/normalized_joinir_min.rs

@@ -20,6 +20,8 @@ use nyash_rust::mir::join_ir::normalized::fixtures::{
     build_pattern4_continue_min_structured_for_normalized_dev,
     build_pattern_continue_return_min_structured_for_normalized_dev,
     build_parse_string_composite_min_structured_for_normalized_dev,
+    build_parse_array_min_structured_for_normalized_dev,
+    build_parse_object_min_structured_for_normalized_dev,
     build_selfhost_args_parse_p2_structured_for_normalized_dev,
     build_selfhost_if_sum_p3_ext_structured_for_normalized_dev,
     build_selfhost_if_sum_p3_structured_for_normalized_dev,

tests/normalized_joinir_min/shapes.rs

@@ -366,7 +366,7 @@ fn test_phase88_jsonparser_unescape_string_step2_min_rejects_non_const_then_i_up
     assert!(res.is_err(), "expected fail-fast panic");
     let msg = panic_message(res.err().unwrap());
     assert!(
-        msg.contains("then i update of form (i + const)"),
+        msg.contains("then' branch step increment") || msg.contains("then i update of form (i + const)"),
         "unexpected panic message: {}",
         msg
     );
@@ -616,3 +616,73 @@ fn test_continue_return_multi_min_returns_null_at_first_match() {
     // - Refactor-B: Multiple return-if with same value (i==3, i==7 both return null)
     assert_eq!(result, JoinValue::Unit, "Expected Unit (null) from first return-if at i=3");
 }
+
+/// Phase Next: Parse Array minimal - vm_bridge direct vs structured
+#[test]
+fn test_parse_array_min_vm_bridge_direct_matches_structured() {
+    use nyash_rust::mir::join_ir::normalized::dev_fixtures::NormalizedDevFixture;
+
+    let _ctx = normalized_dev_test_ctx();
+    let structured = NormalizedDevFixture::ParseArrayMin.load_and_lower();
+    let entry = structured.entry.expect("entry required");
+
+    let input = [JoinValue::Int(10)];
+    let base = run_joinir_vm_bridge(&structured, entry, &input, false);
+    let dev = run_joinir_vm_bridge(&structured, entry, &input, true);
+
+    assert_eq!(base, dev, "vm bridge mismatch for parse_array min");
+}
+
+/// Phase Next: Parse Array minimal - expected output test
+#[test]
+fn test_parse_array_min_expected_output() {
+    use nyash_rust::mir::join_ir::normalized::dev_fixtures::NormalizedDevFixture;
+
+    let _ctx = normalized_dev_test_ctx();
+    let structured = NormalizedDevFixture::ParseArrayMin.load_and_lower();
+    let entry = structured.entry.expect("entry required");
+
+    let input = [JoinValue::Int(10)];
+    let result = run_joinir_vm_bridge(&structured, entry, &input, true);
+
+    assert_eq!(
+        result,
+        JoinValue::Int(6),
+        "Expected acc=6 for n=10 (i=0,1,2,4,5,6 increments, i=3 continue, i=7 return)"
+    );
+}
+
+/// Phase Next: Parse Object minimal - vm_bridge direct vs structured
+#[test]
+fn test_parse_object_min_vm_bridge_direct_matches_structured() {
+    use nyash_rust::mir::join_ir::normalized::dev_fixtures::NormalizedDevFixture;
+
+    let _ctx = normalized_dev_test_ctx();
+    let structured = NormalizedDevFixture::ParseObjectMin.load_and_lower();
+    let entry = structured.entry.expect("entry required");
+
+    let input = [JoinValue::Int(10)];
+    let base = run_joinir_vm_bridge(&structured, entry, &input, false);
+    let dev = run_joinir_vm_bridge(&structured, entry, &input, true);
+
+    assert_eq!(base, dev, "vm bridge mismatch for parse_object min");
+}
+
+/// Phase Next: Parse Object minimal - expected output test
+#[test]
+fn test_parse_object_min_expected_output() {
+    use nyash_rust::mir::join_ir::normalized::dev_fixtures::NormalizedDevFixture;
+
+    let _ctx = normalized_dev_test_ctx();
+    let structured = NormalizedDevFixture::ParseObjectMin.load_and_lower();
+    let entry = structured.entry.expect("entry required");
+
+    let input = [JoinValue::Int(10)];
+    let result = run_joinir_vm_bridge(&structured, entry, &input, true);
+
+    assert_eq!(
+        result,
+        JoinValue::Int(7),
+        "Expected acc=7 for n=10 (i=0,1,2,3,5,6,7 increments, i=4 continue, i=8 return)"
+    );
+}