Add JPMS compatibility to Jackson JSON mapper

Expected Behavior

Applications using the MCP Java SDK should work with JPMS (Java Platform Module System) without requiring --add-opens JVM flags. Record deserialization should work through public constructors and parameter name discovery rather than reflective access.

  // Should work without --add-opens flags
  McpJsonMapper mapper = new JacksonMcpJsonMapperSupplier().get();
  MyRecord record = mapper.readValue(json, MyRecord.class);

Current Behavior

The JacksonMcpJsonMapperSupplier creates a plain ObjectMapper that uses reflection to access record constructors. This requires --add-opens JVM flags like:

  --add-opens java.base/java.lang.reflect=ALL-UNNAMED

Without these flags, deserialization of Java records fails with InaccessibleObjectException.

Context

We're integrating the MCP SDK into a JPMS-modularized application and cannot use --add-opens flags as they break module encapsulation.

The fix is straightforward:

1. Disable MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS to prevent setAccessible() calls
2. Add ParameterNamesModule to discover constructor parameters from bytecode

The SDK already compiles with -parameters, so ParameterNamesModule will work without additional configuration.

Workaround: We currently maintain a custom MCP client with JPMS-compatible Jackson configuration, but would prefer to use the upstream SDK directly.

I have a PR.

从 JacksonMcpJsonMapperSupplier 开始，检查其 ObjectMapper 如何处理 record 构造函数和参数名。对照 JPMS 示例验证 mapper 配置，然后确认 record 反序列化无需 --add-opens 标志即可正常工作，并保持现有行为。