feat(joinir): Phase 213-2 Step 2-2 & 2-3 Data structure extensions

Extended PatternPipelineContext and CarrierUpdateInfo for Pattern 3 AST-based generalization.

Changes:
1. PatternPipelineContext:
   - Added loop_condition: Option<ASTNode>
   - Added loop_body: Option<Vec<ASTNode>>
   - Added loop_update_summary: Option<LoopUpdateSummary>
   - Updated build_pattern_context() for Pattern 3

2. CarrierUpdateInfo:
   - Added then_expr: Option<ASTNode>
   - Added else_expr: Option<ASTNode>
   - Updated analyze_loop_updates() with None defaults

Status: Phase 213-2 Steps 2-2 & 2-3 complete
Next: Create Pattern3IfAnalyzer to extract if statement and populate update summary

tools/pyc/README.md

@@ -11,7 +11,7 @@
 ```bash
 # 1) NYASH_PY_CODE に Python コードを入れる（Parserプラグインが拾う）
 NYASH_PY_CODE=$'def main():\n    return 0' \
-  ./target/release/nyash --backend vm tools/pyc/pyc.hako
+  ./target/release/hakorune --backend vm tools/pyc/pyc.hako
 ```
 
 出力

tools/pyc/pyc.hako

@@ -1,7 +1,7 @@
 // Nyash Python Compiler entry (Phase 10.7 workbench)
 // Nyash-only pipeline: Parser/Compiler are implemented in Nyash using PyRuntimeBox
 // Usage:
-//   NYASH_PY_CODE=$'def main():\n    return 0' ./target/release/nyash --backend vm tools/pyc/pyc.hako
+//   NYASH_PY_CODE=$'def main():\n    return 0' ./target/release/hakorune --backend vm tools/pyc/pyc.hako
 
 static box Main {
   main() {