[ContentUnderstanding] Add LlmInputHelper for converting analysis results to LLM-friendly text

[chienyuanchang]

Description

Adds a toLlmInput helper that converts AnalysisResult into text that LLMs can consume directly — YAML front matter (content type, pages, extracted fields, optional metadata) followed by the markdown body. Useful for injecting into LLM prompts, storing in vector databases, or passing as agentic tool output.

Works with all content types (documents, images, audio, video), multi-segment results (e.g., video scenes), and classification hierarchies (auto-expands parent into per-segment blocks with category labels).

API Surface

public final class LlmInputHelper {
    public static String toLlmInput(AnalysisResult result);
    public static String toLlmInput(AnalysisResult result, Map<String, Object> metadata);
    public static String toLlmInput(AnalysisResult result, Map<String, Object> metadata, ToLlmInputOptions options);
}

public final class ToLlmInputOptions {
public boolean isIncludeFields(); // default: true
public ToLlmInputOptions setIncludeFields(boolean includeFields);
public boolean isIncludeMarkdown(); // default: true
public ToLlmInputOptions setIncludeMarkdown(boolean includeMarkdown);
}

Three overloads follow Java conventions (no optional parameters). The simpler overloads delegate to the full one with null defaults.

Changes

• New classes: LlmInputHelper, ToLlmInputOptions
• Unit tests: 23 tests covering single/multi-page documents, audio/visual segments, classification, field extraction, metadata validation, page markers, warnings, and edge cases
• Samples: Added Sample_Advanced_ToLlmInput (sync + async) for standalone demos; updated Sample01, Sample03, and Sample05 with toLlmInput integration
• Version: Bumped to 1.1.0-beta.1

Cross-language alignment

This feature is aligned across all four Azure SDK languages:

Language	API Shape
Python	to_llm_input(result, *, include_fields=True, include_markdown=True, metadata=None)
C#	result.ToLlmInput(metadata?, options?) (extension method)
Java	3 overloads: toLlmInput(result), toLlmInput(result, metadata), toLlmInput(result, metadata, options)
JS	toLlmInput(result, options?) (single options bag)

Each language follows its idiomatic patterns — Python uses keyword-only args, C# uses extension methods with optional params, Java uses type-disambiguated overloads, JS uses a single options bag.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull request overview

This PR adds a new public helper API in the Content Understanding Java SDK to convert AnalysisResult into LLM-ready text (YAML front matter + markdown), and updates samples/tests/docs to demonstrate and validate the feature.

Changes:

• Introduces LlmInputHelper and ToLlmInputOptions to render analysis results into a prompt-friendly text format.
• Adds unit tests and sample tests covering documents, content ranges, multi-segment audio/video, and classification scenarios.
• Updates samples, README, and changelog to document and demonstrate toLlmInput.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
sdk/contentunderstanding/azure-ai-contentunderstanding/src/main/java/com/azure/ai/contentunderstanding/models/LlmInputHelper.java	New helper that renders AnalysisResult into YAML front matter + markdown, including segmentation/classification logic.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/main/java/com/azure/ai/contentunderstanding/models/ToLlmInputOptions.java	Options bag controlling whether fields and/or markdown are included.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/LlmInputHelperTest.java	Unit tests validating YAML/markdown rendering across content types and edge cases.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample_Advanced_ToLlmInputTest.java	New sample test validating advanced sync scenarios (options, content ranges, segments, metadata).
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample_Advanced_ToLlmInputAsyncTest.java	New sample test validating advanced async scenarios (options, content ranges, segments, metadata).
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample01_AnalyzeBinaryTest.java	Extends existing sample test to exercise toLlmInput on document analysis results.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample01_AnalyzeBinaryAsyncTest.java	Extends existing async sample test to exercise toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample03_AnalyzeInvoiceTest.java	Extends existing invoice sample test to exercise toLlmInput for field extraction results.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/test/java/com/azure/ai/contentunderstanding/tests/samples/Sample03_AnalyzeInvoiceAsyncTest.java	Extends existing async invoice sample test to exercise toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample_Advanced_ToLlmInput.java	New advanced sync sample demonstrating options, content ranges, multi-segment media, and metadata.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample_Advanced_ToLlmInputAsync.java	New advanced async sample demonstrating the same scenarios as the sync sample.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample01_AnalyzeBinary.java	Updates sample to show generating LLM-ready output via toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample01_AnalyzeBinaryAsync.java	Updates async sample to show generating LLM-ready output via toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample03_AnalyzeInvoice.java	Updates sample to show generating LLM-ready output via toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample03_AnalyzeInvoiceAsync.java	Updates async sample to show generating LLM-ready output via toLlmInput.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample05_CreateClassifier.java	Updates classifier sample to route Invoice segments and demonstrate toLlmInput on classification output.
sdk/contentunderstanding/azure-ai-contentunderstanding/src/samples/java/com/azure/ai/contentunderstanding/samples/Sample05_CreateClassifierAsync.java	Updates async classifier sample to analyze and print LLM-ready text for classification output.
sdk/contentunderstanding/azure-ai-contentunderstanding/README.md	Adds README section documenting LlmInputHelper.toLlmInput() with example output and link to advanced sample.
sdk/contentunderstanding/azure-ai-contentunderstanding/CHANGELOG.md	Adds feature entry for toLlmInput and updates the release header.

[yungshinlintw]

Please address the review comments.