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/exe_first_runner_smoke.sh

@@ -15,9 +15,10 @@ echo 'return 1+2*3' > tmp/exe_first_runner_smoke.hako
 
 echo "[3/4] Run nyash with EXE-first parser ..."
 cargo build --release >/dev/null
+BIN=${NYASH_BIN:-./target/release/hakorune}
 set +e
 NYASH_USE_NY_COMPILER=1 NYASH_USE_NY_COMPILER_EXE=1 \
-  ./target/release/nyash --backend vm tmp/exe_first_runner_smoke.hako >/dev/null
+  "$BIN" --backend vm tmp/exe_first_runner_smoke.hako >/dev/null
 RC=$?
 set -e
 
@@ -29,4 +30,3 @@ fi
 
 echo "✅ Runner EXE-first smoke passed"
 exit 0
-