feat(anf): Phase 146/147 - Loop/If Condition ANF with Compare support

## Phase 146 P0: ANF Routing SSOT Unified

**Goal**: Unify ANF routing in `lower_expr_with_scope()` L54-84, remove legacy lowering

**Changes**:
- expr_lowerer_box.rs: Added scope check (PureOnly → skip ANF, WithImpure → try ANF)
- post_if_post_k.rs: Removed legacy inline lowering (L271-285), added `lower_condition_legacy()` helper
- contract.rs: Already had `CondLoweringFailed` out-of-scope reason

**Test Results**: ✅ Phase 146 P0 smoke (exit 7), 0 regressions

## Phase 146 P1: Compare Operator Support

**Goal**: Enable ANF for condition expressions with Compare operators

**Changes**:
- joinir_dev.rs: Added `anf_allow_pure_enabled()` (HAKO_ANF_ALLOW_PURE=1)
- expr_lowerer_box.rs: PureOnly scope ANF support (L56-66)
- execute_box.rs: Compare operator support (+122 lines)
  - `execute_compare_hoist()`, `execute_compare_recursive()`, `ast_compare_to_joinir()`
  - Extended `normalize_and_lower()` for Compare

**Test Results**: ✅ Phase 146 P1 smoke (exit 7 with flags), 0 regressions

## Phase 147 P0: Recursive Comparison ANF

**Goal**: Extend recursive ANF to Compare operators

**Changes**:
- contract.rs: Added `AnfParentKind::Compare` variant
- plan_box.rs: Compare case in BinaryOp routing (L68-79, L134-139)
  - Distinguishes Compare vs arithmetic BinaryOp

**Benefits**: Enables recursive ANF for comparisons
- `s.length() == 3` → `t = s.length(); if (t == 3)` ✅
- `s1.length() < s2.length()` → `t1 = s1.length(); t2 = s2.length(); if (t1 < t2)` ✅

## Implementation Summary

**Files Modified** (9 files, +253 lines, -25 lines = +228 net):
1. src/config/env/joinir_dev.rs (+28 lines)
2. src/mir/control_tree/normalized_shadow/anf/contract.rs (+2 lines)
3. src/mir/control_tree/normalized_shadow/anf/execute_box.rs (+122 lines)
4. src/mir/control_tree/normalized_shadow/anf/plan_box.rs (+18 lines)
5. src/mir/control_tree/normalized_shadow/common/expr_lowerer_box.rs (+18 lines, -0 lines)
6. src/mir/control_tree/normalized_shadow/post_if_post_k.rs (+44 lines, -25 lines)
7. CURRENT_TASK.md
8. docs/development/current/main/10-Now.md
9. docs/development/current/main/30-Backlog.md

**Files Created** (7 files):
- apps/tests/phase146_p0_if_cond_unified_min.hako
- apps/tests/phase146_p1_if_cond_intrinsic_min.hako
- tools/smokes/.../phase146_p0_if_cond_unified_vm.sh
- tools/smokes/.../phase146_p0_if_cond_unified_llvm_exe.sh
- tools/smokes/.../phase146_p1_if_cond_intrinsic_vm.sh
- tools/smokes/.../phase146_p1_if_cond_intrinsic_llvm_exe.sh
- docs/development/current/main/phases/phase-146/README.md

**Acceptance Criteria**: ✅ All met
- cargo build --release: PASS (0 errors, 0 warnings)
- Phase 145 regressions: PASS (exit 12, 18, 5)
- Phase 146 P0: PASS (exit 7)
- Phase 146 P1: PASS (exit 7 with HAKO_ANF_ALLOW_PURE=1)

**Architecture**:
- SSOT: ANF routing only in `lower_expr_with_scope()` L54-84
- Box-First: Phase 145 `anf/` module extended
- Legacy removed: post_if_post_k.rs unified with SSOT

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

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

docs/development/current/main/30-Backlog.md

@@ -8,6 +8,11 @@ Related:
 
 ## 直近（JoinIR/selfhost）
 
+- **収束方針（SSOT案）: Expr/Condition/Control の 3 箱分割**
+  - ExprLowererBox（式SSOT）: `AST(expr)` → `(prelude, value)`（ANF含む）。pure/impure/whitelist/strict を集約（入口SSOT）。
+  - ConditionLowererBox（条件→分岐SSOT）: `AST(cond)` → `BranchPlan`。評価順は ExprLowererBox に委譲し、`&&/||` は制御語彙で扱う。
+  - ControlLowererBox（制御SSOT）: `StepNode/ControlTree` → JoinIR（継続 + env）。`if/loop` を担当し、条件は ConditionLowererBox に委譲。
+
 - **Phase 141 P2+（planned）: Call/MethodCall（effects + typing を分離して段階投入）**
   - ねらい: pure/impure 境界を壊さずに、impure lowering を段階投入する。
   - 前提（DONE）: