test(joinir): Fix phase212 test to use Main box pattern

Changed IfSumTest to Main box with main(args) to match entry point
convention. Removed print() calls that aren't needed for RC test.

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

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

apps/tests/phase212_if_sum_min.hako

@@ -1,15 +1,14 @@
-// Phase 212: Pattern 1 + Pattern 3 (IfPHI) test - if-sum implementation
+// Phase 212: Pattern 3 (IfPHI) test - if-sum implementation
 // Tests: Loop with conditional update inside if block
 // Target: selfhost if-sum pattern (e.g., FuncScannerBox._sum_def_count)
 //
 // Expected behavior:
-//   Array [null-equivalent, "a", "b"] → sum counts non-empty strings
-//   Empty string "" treated as null-equivalent → skip
-//   "a", "b" are valid → sum = 2
+//   Simulated array [null-equivalent, "a", "b"] → sum counts non-empty strings
+//   i=0 → skip, i=1,2 → count
 //
-// Expected result: 2 (count of valid items)
+// Expected result: RC=2 (count of valid items)
 
-static box IfSumTest {
+static box Main {
     sum_def_count(defs) {
         local sum
         sum = 0
@@ -19,10 +18,6 @@ static box IfSumTest {
         len = 3
 
         loop(i < len) {
-            // ArrayBox.get equivalent (simplified: use index directly)
-            // In real code: local item = defs.get(i)
-            // For Phase 212: simulate with positional check
-
             // Simulate: [empty, "a", "b"]
             //   i=0 → empty (skip)
             //   i=1 → "a" (count)
@@ -31,9 +26,9 @@ static box IfSumTest {
             if i > 0 {
                 // Conditional update: sum = sum + 1
                 sum = sum + 1
-                print(sum)  // ← Force if to stay in MIR
             } else {
-                print(0)  // ← Ensure else branch exists
+                // Else branch (do nothing)
+                sum = sum + 0
             }
 
             i = i + 1
@@ -42,11 +37,10 @@ static box IfSumTest {
         return sum
     }
 
-    main() {
-        // Array: [empty, "a", "b"] → sum=2
-        // (simplified without actual ArrayBox for Phase 212)
+    main(args) {
+        // Simulated array [empty, "a", "b"] → sum=2
         local result
-        result = IfSumTest.sum_def_count(0)  // dummy arg
+        result = Main.sum_def_count(0)  // dummy arg
         return result
     }
 }