🔧 Hotfix 7 (Enhanced): ValueId receiver alias tracking for nested loops

- Problem: Pinned receiver variables in loops cause undefined ValueId errors
- Enhanced fix: Update all receiver aliases (me + all __pin$N$@recv levels)
- Handles nested loops by updating previous pin levels
- Test status: Partial improvement, ValueId(50) → ValueId(40)
- Further investigation needed for complete fix

Files modified:
- src/mir/phi_core/loopform_builder.rs (emit_header_phis)

src/mir/phi_core/loopform_builder.rs

@@ -217,6 +217,32 @@ impl LoopFormBuilder {
                 vec![(self.preheader_id, pinned.preheader_copy)],
             )?;
             ops.update_var(pinned.name.clone(), pinned.header_phi);
+
+            // 🔧 Hotfix 7 (Enhanced): Update aliases for pinned receiver variables
+            // When a variable like "me" is pinned to "__pin$N$@recv", both names
+            // must point to the same PHI value to avoid stale ValueId references.
+            // This handles:
+            // 1. Direct receiver: "me" → "__pin$1$@recv"
+            // 2. Nested loops: "__pin$1$@recv" → "__pin$2$@recv"
+            // 3. Multiple aliasing scenarios
+            if pinned.name.contains("@recv") {
+                // Always update "me" (the canonical receiver name)
+                ops.update_var("me".to_string(), pinned.header_phi);
+
+                // Also update all previous pin levels (__pin$1$@recv, __pin$2$@recv, etc.)
+                // Extract the pin counter and update all lower levels
+                if let Some(idx) = pinned.name.find("$") {
+                    if let Some(end_idx) = pinned.name[idx+1..].find("$") {
+                        if let Ok(counter) = pinned.name[idx+1..idx+1+end_idx].parse::<u32>() {
+                            // Update all previous pin levels (1 through counter-1)
+                            for i in 1..counter {
+                                let alias = format!("__pin${}$@recv", i);
+                                ops.update_var(alias, pinned.header_phi);
+                            }
+                        }
+                    }
+                }
+            }
         }
 
         // Emit PHIs for carrier variables