test: add phase95 json_loader escape fixture

apps/tests/phase95_json_loader_escape_min.hako

@@ -0,0 +1,34 @@
+// Phase 95: json_loader escape loop (minimal)
+// Purpose: Fixture extracted from MiniJsonLoader.read_quoted_from to exercise
+//          Phase 94 derived body-local + conditional skip in JoinIR.
+
+static box Main {
+    main() {
+        // Input mirrors the json_loader escape case
+        local s = "\"hello\\\" world\""
+        local pos = 0
+        local i = pos
+        if s.substring(i, i + 1) != "\"" { return "NG" }
+        i = i + 1
+        local out = ""
+        local n = s.length()
+
+        loop(i < n) {
+            local ch = s.substring(i, i + 1)
+            if ch == "\"" { break }
+
+            if ch == "\\" {
+                i = i + 1
+                if i < n {
+                    ch = s.substring(i, i + 1)
+                }
+            }
+
+            out = out + ch
+            i = i + 1
+        }
+
+        print(out)
+        return "OK"
+    }
+}