sealed: add release-level and Jackson 3.2.3 transcripts

09 shows which language level each sealed feature needs; 10 runs the Payment model through Jackson 3 (jars fetched and sha1-checked, not committed).

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a

sealed/jackson/JsonForgotten.java

@@ -0,0 +1,25 @@
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import tools.jackson.databind.json.JsonMapper;
+
+public class JsonForgotten {
+    // Wallet is a permitted subtype, and the compiler is happy, but nobody told Jackson about it.
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
+    @JsonSubTypes({
+        @JsonSubTypes.Type(value = Card.class, name = "card"),
+        @JsonSubTypes.Type(value = Upi.class, name = "upi")})
+    sealed interface Payment permits Card, Upi, Wallet {}
+    record Card(long amount) implements Payment {}
+    record Upi(long amount) implements Payment {}
+    record Wallet(long amount) implements Payment {}
+
+    public static void main(String[] args) {
+        JsonMapper mapper = JsonMapper.builder().build();
+        System.out.println("write : " + mapper.writeValueAsString(new Wallet(500)));
+        try {
+            mapper.readValue("{\"type\":\"wallet\",\"amount\":500}", Payment.class);
+        } catch (Exception e) {
+            System.out.println("read  : " + e.getClass().getSimpleName() + ": " + e.getMessage().lines().findFirst().orElse(""));
+        }
+    }
+}