docs: Phase 190-impl-D complete - NumberAccumulation PHI wiring fixed

- Fixed ValueId collision between body-local and carrier params
- Added ExitLine contract verifier (debug assertions)
- Updated test files to use Main box
- E2E verified: atoi→12, parse_number→123

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

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

apps/tests/phase190_atoi_impl.hako

@@ -4,9 +4,16 @@
 //
 // Note: Phase 190-impl-D found that body-local variable support is incomplete.
 // Using loop variable directly for now.
+//
+// Expected calculation:
+//   i=0: result = 0*10 + 0 = 0
+//   i=1: result = 0*10 + 1 = 1
+//   i=2: result = 1*10 + 2 = 12
+//   i=3: break (condition i >= 3)
+// Expected result: 12
 
-static box AtoiImpl {
-    method main() {
+static box Main {
+    main() {
         local result
         result = 0
         local i
@@ -19,6 +26,7 @@ static box AtoiImpl {
             result = result * 10 + i
             i = i + 1
         }
-        return result
+        print(result)
+        return 0
     }
 }

apps/tests/phase190_parse_number_impl.hako

@@ -5,8 +5,8 @@
 // Expected: i=1,2,3 → num = 0*10+1 = 1 → 1*10+2 = 12 → 12*10+3 = 123
 // Result should be 123
 
-static box ParseNumberImpl {
-    method main() {
+static box Main {
+    main() {
         local num
         num = 0
         local i
@@ -19,6 +19,6 @@ static box ParseNumberImpl {
             i = i + 1
         }
         print(num)
-        return num
+        return 0
     }
 }