fix(joinir): Phase 269 P1.2 - static call normalization for this.method()

Problem:
- `this.method()` calls in static box loops were using string constant "StringUtils" as receiver
- This violated Box Theory (static box this should not be runtime object)
- Pattern8 was trying to pass receiver to JoinIR, causing SSA/PHI issues

Solution (3-part fix):
1. **MeResolverBox Fail-Fast** (stmts.rs): Remove string fallback, error message cleanup
2. **ReceiverNormalizeBox** (calls/build.rs): Normalize `this/me.method()` → static call at compile-time
3. **Pattern8 Skip Static Box** (pattern8_scan_bool_predicate.rs): Reject Pattern8 for static box contexts

Key changes:
- **stmts.rs**: Update error message - remove MeBindingInitializerBox mentions
- **calls/build.rs**: Add This/Me receiver check, normalize to static call if current_static_box exists
- **calls/lowering.rs**: Remove NewBox-based "me" initialization (2 locations - fixes Stage1Cli regression)
- **pattern8_scan_bool_predicate.rs**: Skip Pattern8 for static boxes (use Pattern1 fallback instead)

Result:
- ✅ phase269_p1_2_this_method_in_loop_vm.sh PASS (exit=7)
- ✅ No regression: phase259_p0_is_integer_vm PASS
- ✅ No regression: phase269_p0_pattern8_frag_vm PASS
- ✅ Stage1Cli unit tests PASS
- ✅ MIR uses CallTarget::Global, no const "StringUtils" as receiver

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

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

src/mir/builder/control_flow/joinir/patterns/pattern8_scan_bool_predicate.rs

@@ -56,7 +56,21 @@ struct BoolPredicateScanParts {
 
 /// Phase 269 P1: Detection for Pattern 8 (BoolPredicateScan)
 /// Now uses EdgeCFG Frag lowering via emission entrypoint
-pub(crate) fn can_lower(_builder: &MirBuilder, ctx: &super::router::LoopPatternContext) -> bool {
+/// Phase 269 P1.2: Skip Pattern8 for static box this.method() - let ReceiverNormalizeBox handle
+pub(crate) fn can_lower(builder: &MirBuilder, ctx: &super::router::LoopPatternContext) -> bool {
+    // Phase 269 P1.2: Skip Pattern8 for static box contexts
+    // this.method() in static boxes should be normalized to static calls by ReceiverNormalizeBox
+    // Pattern8 requires a receiver object, which doesn't exist for static box methods
+    if builder.comp_ctx.current_static_box.is_some() {
+        if ctx.debug {
+            trace::trace().debug(
+                "pattern8/can_lower",
+                "reject: static box context (ReceiverNormalizeBox handles this.method())",
+            );
+        }
+        return false;
+    }
+
     match extract_bool_predicate_scan_parts(ctx.condition, ctx.body) {
         Ok(Some(_)) => {
             if ctx.debug {
@@ -159,10 +173,16 @@ fn extract_bool_predicate_scan_parts(
                 {
                     // Extract receiver (e.g., "me")
                     // Phase 259 P0: Support both Variable and Me node
+                    // Phase 269 P1.2: Skip This in static box context (handled by ReceiverNormalizeBox)
                     // IMPORTANT: Me is registered as "me" in variable_map (not "this")
                     let receiver = match object.as_ref() {
                         ASTNode::Variable { name, .. } => name.clone(),
                         ASTNode::Me { .. } => "me".to_string(),  // Me is registered as "me" in MirBuilder
+                        ASTNode::This { .. } => {
+                            // Phase 269 P1.2: Skip pattern for This in static box context
+                            // Let ReceiverNormalizeBox handle static call normalization instead
+                            continue;
+                        }
                         _ => continue,
                     };