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/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> {