feat(mir): Phase 92 P2-2 - Body-local variable support for ConditionalStep

Phase 92 P2-2完了：ConditionalStepのcondition（ch == '\\'など）でbody-local変数をサポート

## 主要変更

### 1. condition_lowerer.rs拡張
- `lower_condition_to_joinir`に`body_local_env`パラメータ追加
- 変数解決優先度：ConditionEnv → LoopBodyLocalEnv
- すべての再帰ヘルパー（comparison, logical_and, logical_or, not, value_expression）対応

### 2. conditional_step_emitter.rs修正
- `emit_conditional_step_update`に`body_local_env`パラメータ追加
- condition loweringにbody-local環境を渡す

### 3. loop_with_break_minimal.rs修正
- break condition loweringをbody-local init の**後**に移動（line 411）
- header_break_lowering::lower_break_conditionにbody_local_env渡す
- emit_conditional_step_updateにbody_local_env渡す（line 620）

### 4. header_break_lowering.rs修正
- `lower_break_condition`に`body_local_env`パラメータ追加
- scope_managerにbody-local環境を渡す

### 5. 全呼び出し箇所修正
- expr_lowerer.rs (2箇所)
- method_call_lowerer.rs (2箇所)
- loop_with_if_phi_if_sum.rs (3箇所)
- loop_with_continue_minimal.rs (1箇所)
- carrier_update_emitter.rs (1箇所・legacy)

## アーキテクチャ改善

### Break Condition Lowering順序修正
旧: Header → **Break Cond** → Body-local Init
新: Header → **Body-local Init** → Break Cond

理由：break conditionが`ch == '\"'`のようにbody-local変数を参照する場合、body-local initが先に必要

### 変数解決優先度（Phase 92 P2-2）
1. ConditionEnv（ループパラメータ、captured変数）
2. LoopBodyLocalEnv（body-local変数like `ch`）

## テスト

### ビルド
✅ cargo build --release成功（30 warnings、0 errors）

### E2E
⚠️ body-local promotion問題でブロック（Phase 92範囲外）
- Pattern2はbody-local変数をcarrier promotionする必要あり
- 既存パターン（A-3 Trim, A-4 DigitPos）に`ch = get_char(i)`が該当しない
- **Phase 92 P2-2目標（condition loweringでbody-local変数サポート）は達成**

## 次タスク（Phase 92 P3以降）
- body-local variable promotion拡張（Pattern2で`ch`のような変数を扱う）
- P5b E2Eテスト完全動作確認

## Phase 92 P2-2完了
✅ Body-local変数のcondition lowering対応完了
✅ ConditionalStepでbody-local変数参照可能
✅ Break condition lowering順序修正

apps/tests/test_pattern5b_minimal_p2.hako

@@ -0,0 +1,50 @@
+// Phase 92 P2-3: Minimal P5b E2E Test
+//
+// This is a MINIMAL test to verify ConditionalStep emission works.
+// Pattern: Loop with break check + conditional increment (P5b escape pattern)
+//
+// Expected behavior:
+// - i=0: not quote, not escape, i=1
+// - i=1: not quote, not escape, i=2
+// - i=2: not quote, IS escape, i=4
+// - i=4: IS quote, break
+// - Output: 4
+
+static box Main {
+    main() {
+        local i = 0
+        local len = 10
+        local ch = "a"
+        local str = "ab\\cd\"ef"
+
+        loop(i < len) {
+            // Body statement: Simulate character access from string
+            // In real parser, this would be: ch = str.charAt(i)
+            // Here we simplify by checking position
+            if i == 2 {
+                ch = "\\"  // Position 2: backslash
+            } else {
+                if i == 4 {
+                    ch = "\""  // Position 4: quote
+                } else {
+                    ch = "a"  // Other positions: normal char
+                }
+            }
+
+            // Break check (P5b pattern requirement)
+            if ch == "\"" {
+                break
+            }
+
+            // Escape check with conditional increment (P5b pattern)
+            if ch == "\\" {
+                i = i + 2  // Escape: skip 2
+            } else {
+                i = i + 1  // Normal: skip 1
+            }
+        }
+
+        print(i)
+        return 0
+    }
+}

apps/tests/test_pattern5b_recognized.hako

@@ -0,0 +1,52 @@
+// Phase 92 P2-3: P5b Test That Matches Pattern Recognizer
+//
+// This test is designed to exactly match what the pattern recognizer expects:
+// 1. Body statement with simple ch assignment
+// 2. Break check: if ch == "\"" { break }
+// 3. Escape check: if ch == "\\" { i = i + 2 } else { i = i + 1 }
+//
+// Expected behavior (simulated string "a\\b\"c"):
+// - i=0: ch='a', not quote, not escape, i=1
+// - i=1: ch='\\', not quote, IS escape, i=3
+// - i=3: ch='\"', IS quote, break
+// - Output: 3
+
+static box Main {
+    get_char(pos) {
+        // Simulate string access: "a\\b\"c"
+        // Position 0: 'a', Position 1: '\\', Position 3: '\"'
+        if pos == 1 {
+            return "\\"
+        }
+        if pos == 3 {
+            return "\""
+        }
+        return "a"
+    }
+
+    main() {
+        local i = 0
+        local len = 5
+        local ch = "a"
+
+        loop(i < len) {
+            // Body statement: simple assignment (not method call)
+            ch = me.get_char(i)
+
+            // Break check (P5b pattern requirement)
+            if ch == "\"" {
+                break
+            }
+
+            // Escape check with conditional increment (P5b pattern)
+            if ch == "\\" {
+                i = i + 2  // Escape: skip 2
+            } else {
+                i = i + 1  // Normal: skip 1
+            }
+        }
+
+        print(i)
+        return 0
+    }
+}

apps/tests/test_pattern5b_simple.hako

@@ -0,0 +1,38 @@
+// Phase 92 P2-3: Simplest P5b E2E Test (no body-local variables)
+//
+// This test uses position-based checks instead of a 'ch' variable
+// to avoid the body-local variable complexity for initial testing.
+//
+// Pattern: Loop with break check + conditional increment (P5b escape pattern)
+//
+// Expected behavior:
+// - i=0: not quote (0!=4), not escape (0!=2), i=1
+// - i=1: not quote (1!=4), not escape (1!=2), i=2
+// - i=2: not quote (2!=4), IS escape (2==2), i=4
+// - i=4: IS quote (4==4), break
+// - Output: 4
+
+static box Main {
+    main() {
+        local i = 0
+        local len = 10
+
+        loop(i < len) {
+            // Break check (simulated: position 4 is quote)
+            if i == 4 {
+                break
+            }
+
+            // Escape check with conditional increment (P5b pattern)
+            // Position 2 is escape character
+            if i == 2 {
+                i = i + 2  // Escape: skip 2
+            } else {
+                i = i + 1  // Normal: skip 1
+            }
+        }
+
+        print(i)
+        return 0
+    }
+}