Add support for OpenAI web search options and Grok compat

[kzu]

• Add OpenAI/Grok subnamespace: helps organize functionality areas
• Adds OpenAI WebSearchTool-specific extensions under that namespace: region, city, timezone, context size.
• Cross-provider compatibility by interpreting WebSearchTool as GrokSearch(Auto) with a GrokWebSource(country).

[kzu]

🧪 Details on Ubuntu 24.04.2 LTS

from dotnet-retest v0.7.1 on .NET 8.0.17 with 💜 by @devlooped

[Copilot]

Pull Request Overview

Adds support for OpenAI-specific web search options (region, city, timezone, context size) via a new sub-namespace, and ensures Grok compatibility by mapping the same tool to Grok’s live search API.

• Introduces WebSearchTool under Devlooped.Extensions.AI with an extensible Properties bag.
• Supplies OpenAI extensions (Region, City, TimeZone, ContextSize) in Devlooped.Extensions.AI.OpenAI.
• Maps WebSearchTool to GrokChatWebSearchOptions in Devlooped.Extensions.AI.Grok.
• Adjusts namespaces for OpenAI/Grok client types and updates README with usage examples.

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/AI/WebSearchTool.cs	Implements WebSearchTool with base country filtering and property bag.
src/AI/OpenAI/WebSearchToolExtensions.cs	Adds extension block for WebSearchTool to configure region, city, timezone, and context size.
src/AI/OpenAI/OpenAIChatClient.cs	Moves OpenAIChatClient into the OpenAI sub-namespace.
src/AI/Grok/GrokSearchTool.cs	Relocates GrokSearchTool into the Grok sub-namespace.
src/AI/Grok/GrokClient.cs	Maps WebSearchTool under GrokChatClient to GrokWebSource; qualifies global::OpenAI.
src/AI/Grok/GrokChatOptions.cs	Moves GrokChatOptions into the Grok sub-namespace.
src/AI/Grok/GrokChatClient.cs	Adds handling for WebSearchTool in the pipeline; global-qualifies OpenAI types.
src/AI.Tests/ToolsTests.cs	Updates tests to qualify OpenAIClientOptions with global::OpenAI.
src/AI.Tests/RetrievalTests.cs	Qualifies OpenAIClientOptions and FileUploadPurpose with global::OpenAI.
src/AI.Tests/OpenAITests.cs	Adds a live-search test using WebSearchTool; imports updated OpenAI namespace.
src/AI.Tests/GrokTests.cs	Qualifies OpenAIClientOptions import and ensures Grok namespace usage.
readme.md	Documents WebSearchTool usage for both OpenAI and Grok clients with examples.

Comments suppressed due to low confidence (4)

src/AI/WebSearchTool.cs:7

• [nitpick] The summary only mentions country filtering. Update it to reflect that this tool also supports region, city, timezone, and context size.

/// Basic web search tool that can limit the search to a specific country.

src/AI/OpenAI/WebSearchToolExtensions.cs:32

• No tests cover the Region property; consider adding unit tests to verify that setting Region correctly updates both Properties and the underlying Location.

        public string? Region

src/AI/WebSearchTool.cs:12

• The private field region is declared but never used. Consider removing it to reduce dead code.

    string? region;

src/AI.Tests/OpenAITests.cs:99

• The test references WebSearchTool but only imports Devlooped.Extensions.AI.OpenAI. You need using Devlooped.Extensions.AI; (or fully qualify) so that WebSearchTool resolves correctly.

            Tools = [new WebSearchTool("AR")