…, and use JSpecify Nullable

- Migrate LangChain4j to a builder pattern
- Enhance token usage handling with TokenCountEstimator (from PR google#623)
- Upgrade to latest version of LangChain4j
- Replace javax.annotation.Nullable with org.jspecify.annotations.Nullable

PiperOrigin-RevId: 886828787

PiperOrigin-RevId: 886942637

Ensure sequential event processing and persistence in ADK Runner. This
ensures that events are appended in order and returned from runAsync in
order. This aligns better with the Python implementation.

PiperOrigin-RevId: 886961696

…(PR google#1035)

PiperOrigin-RevId: 887389399

…already implemented, but adding tests from PR google#603)

PiperOrigin-RevId: 888064419

The `slf4j-simple` dependency and the exclusion of `logback-classic` are removed, allowing the default logging implementation provided by `google-adk-dev` to be used.

PiperOrigin-RevId: 888114465

…i module

PiperOrigin-RevId: 888625731

PiperOrigin-RevId: 888626578

PiperOrigin-RevId: 888667558

PiperOrigin-RevId: 889140710

The Claude model integration parsing logic failed when processing MCP tool responses because it only extracted output from the legacy `result` field. Extended extraction logic to:
- Support native MCP `content` arrays.
- Support legacy `result` structures natively.
- Fallback to generic JSON serialization of the entire map.
Additionally, updated AbstractMcpTool.wrapCallResult() format to match Python ADK.

PiperOrigin-RevId: 889141233

…-remove

PiperOrigin-RevId: 889207343

Previously, MessageConverter only transferred text content from ADK to Spring AI,
ignoring image and media attachments. This caused vision model requests to fail
even though Spring AI's underlying models (like GPT-4o) support image inputs.

Updated MessageConverter to properly handle image/media parts by constructing
UserMessage with Media attachments.

Fixes google#705

…ia-support

PiperOrigin-RevId: 889231825