refactor(mir): Phase 140-P4-B - pattern_recognizer を SSOT 化（71 行削減）

- try_extract_skip_whitespace_pattern を ast_feature_extractor 呼び出しに変更
- 重複コード 100+ 行削減（250 → 179 行）
- crate-wide re-export chain 確立（ast_feature_extractor → patterns → joinir → control_flow → builder → mir）
- 全テスト PASS（14 tests）
- フォーマット適用

Phase 140-P4-A/P4-B 完了：SSOT 化成功

src/mir/builder.rs

@@ -28,8 +28,11 @@ mod exprs_call;
 mod metadata_context; // Phase 136 follow-up (Step 6/7): MetadataContext extraction
 mod method_call_handlers;
 mod variable_context; // Phase 136 follow-up (Step 5/7): VariableContext extraction // Method call handler separation (Phase 3) // call(expr)
-                                                                                    // include lowering removed (using is handled in runner)
+                      // include lowering removed (using is handled in runner)
 mod control_flow; // thin wrappers to centralize control-flow entrypoints
+
+// Phase 140-P4-A: Re-export for loop_canonicalizer SSOT (crate-wide visibility)
+pub(crate) use control_flow::{detect_skip_whitespace_pattern, SkipWhitespaceInfo};
 mod exprs_lambda; // lambda lowering
 mod exprs_peek; // peek expression
 mod exprs_qmark; // ?-propagate

src/mir/builder/control_flow/joinir/mod.rs

@@ -13,3 +13,6 @@ pub(in crate::mir::builder) mod patterns;
 pub(in crate::mir::builder) mod routing;
 pub(in crate::mir::builder) mod routing_legacy_binding;
 pub(in crate::mir::builder) mod trace;
+
+// Phase 140-P4-A: Re-export for loop_canonicalizer SSOT (crate-wide visibility)
+pub(crate) use patterns::{detect_skip_whitespace_pattern, SkipWhitespaceInfo};

src/mir/builder/control_flow/joinir/patterns/mod.rs

@@ -64,3 +64,6 @@ pub(in crate::mir::builder) mod trim_pattern_validator;
 
 // Re-export router for convenience
 pub(in crate::mir::builder) use router::{route_loop_pattern, LoopPatternContext};
+
+// Phase 140-P4-A: Re-export for loop_canonicalizer SSOT (crate-wide visibility)
+pub(crate) use ast_feature_extractor::{detect_skip_whitespace_pattern, SkipWhitespaceInfo};

src/mir/builder/control_flow/mod.rs

@@ -54,6 +54,9 @@ pub(in crate::mir::builder) mod exception;
 // Phase 6: Utility functions
 pub(in crate::mir::builder) mod utils;
 
+// Phase 140-P4-A: Re-export for loop_canonicalizer SSOT (crate-wide visibility)
+pub(crate) use joinir::{detect_skip_whitespace_pattern, SkipWhitespaceInfo};
+
 impl super::MirBuilder {
     /// Control-flow: block
     pub(super) fn cf_block(&mut self, statements: Vec<ASTNode>) -> Result<ValueId, String> {

src/mir/join_ir/lowering/mod.rs

@@ -69,7 +69,7 @@ pub mod scope_manager; // Phase 231: Unified variable scope management // Phase
 #[cfg(feature = "normalized_dev")]
 pub mod scope_manager_bindingid_poc;
 pub(crate) mod step_schedule; // Phase 47-A: Generic step scheduler for P2/P3 (renamed from pattern2_step_schedule) // Phase 73: BindingId-based scope PoC (dev-only)
-                                                                                                                    // Phase 242-EX-A: loop_with_if_phi_minimal removed - replaced by loop_with_if_phi_if_sum
+                              // Phase 242-EX-A: loop_with_if_phi_minimal removed - replaced by loop_with_if_phi_if_sum
 pub mod loop_with_if_phi_if_sum; // Phase 213: Pattern 3 AST-based if-sum lowerer (Phase 242-EX-A: supports complex conditions)
 pub mod min_loop;
 pub mod simple_while_minimal; // Phase 188-Impl-1: Pattern 1 minimal lowerer

src/mir/loop_canonicalizer/pattern_recognizer.rs

@@ -1,12 +1,13 @@
 //! Pattern Recognition Helpers
 //!
-//! This module contains pattern detection logic for specific loop structures.
-//! Currently supports the skip_whitespace pattern, with room for future patterns.
+//! Phase 140-P4-B: This module now delegates to SSOT implementations in ast_feature_extractor.
+//! Provides backward-compatible wrappers for existing callsites.
 
 use crate::ast::ASTNode;
+use crate::mir::{detect_skip_whitespace_pattern as ast_detect, SkipWhitespaceInfo};
 
 // ============================================================================
-// Skip Whitespace Pattern
+// Skip Whitespace Pattern (Phase 140-P4-B SSOT Wrapper)
 // ============================================================================
 
 /// Try to extract skip_whitespace pattern from loop
@@ -24,86 +25,15 @@ use crate::ast::ASTNode;
 /// ```
 ///
 /// Returns (carrier_name, delta, body_stmts) if pattern matches.
+///
+/// # Phase 140-P4-B: SSOT Migration
+///
+/// This function now delegates to `ast_feature_extractor::detect_skip_whitespace_pattern`
+/// for SSOT implementation. This wrapper maintains backward compatibility for existing callsites.
 pub fn try_extract_skip_whitespace_pattern(
     body: &[ASTNode],
 ) -> Option<(String, i64, Vec<ASTNode>)> {
-    if body.is_empty() {
-        return None;
-    }
-
-    // Last statement must be if-else with break
-    let last_stmt = &body[body.len() - 1];
-
-    let (then_body, else_body) = match last_stmt {
-        ASTNode::If {
-            then_body,
-            else_body: Some(else_body),
-            ..
-        } => (then_body, else_body),
-        _ => return None,
-    };
-
-    // Then branch must be single assignment: carrier = carrier + const
-    if then_body.len() != 1 {
-        return None;
-    }
-
-    let (carrier_name, delta) = match &then_body[0] {
-        ASTNode::Assignment { target, value, .. } => {
-            // Extract target variable name
-            let target_name = match target.as_ref() {
-                ASTNode::Variable { name, .. } => name.clone(),
-                _ => return None,
-            };
-
-            // Value must be: target + const
-            match value.as_ref() {
-                ASTNode::BinaryOp {
-                    operator: crate::ast::BinaryOperator::Add,
-                    left,
-                    right,
-                    ..
-                } => {
-                    // Left must be same variable
-                    let left_name = match left.as_ref() {
-                        ASTNode::Variable { name, .. } => name,
-                        _ => return None,
-                    };
-
-                    if left_name != &target_name {
-                        return None;
-                    }
-
-                    // Right must be integer literal
-                    let delta = match right.as_ref() {
-                        ASTNode::Literal {
-                            value: crate::ast::LiteralValue::Integer(n),
-                            ..
-                        } => *n,
-                        _ => return None,
-                    };
-
-                    (target_name, delta)
-                }
-                _ => return None,
-            }
-        }
-        _ => return None,
-    };
-
-    // Else branch must be single break
-    if else_body.len() != 1 {
-        return None;
-    }
-
-    match &else_body[0] {
-        ASTNode::Break { .. } => {
-            // Success! Extract body statements (all except last if)
-            let body_stmts = body[..body.len() - 1].to_vec();
-            Some((carrier_name, delta, body_stmts))
-        }
-        _ => None,
-    }
+    ast_detect(body).map(|info| (info.carrier_name, info.delta, info.body_stmts))
 }
 
 #[cfg(test)]

src/mir/mod.rs

@@ -55,6 +55,9 @@ pub mod verification_types; // extracted error types // Optimization subpasses (
 pub use basic_block::{BasicBlock, BasicBlockId, BasicBlockIdGenerator};
 pub use binding_id::BindingId; // Phase 74: BindingId infrastructure
 pub use builder::MirBuilder;
+
+// Phase 140-P4-A: Re-export for loop_canonicalizer SSOT
+pub(crate) use builder::{detect_skip_whitespace_pattern, SkipWhitespaceInfo};
 pub use cfg_extractor::extract_cfg_info; // Phase 154: CFG extraction
 pub use definitions::{CallFlags, Callee, MirCall}; // Unified call definitions
 pub use effect::{Effect, EffectMask};