Rob Lourens

This commit **resolves a localization bug** affecting the **chat session workspace picker**, specifically addressing the incorrect display of the 'Select {0}' string. It **updates localization keys** within `sessionWorkspacePicker.ts` to ensure proper internationalization and clarity for users. Concurrently, the **developer tooling** is enhanced by extending the `code-no-unexternalized-strings` ESLint rule in `.eslint-plugin-local/code-no-unexternalized-strings.ts` to correctly identify unexternalized template literals. This dual approach not only **fixes an immediate user-facing issue** but also **improves code quality checks** to prevent future localization regressions.

This commit introduces a new **developer action** to inspect **chat model references**, providing crucial insights into their owners, reference counts, and age. It involves extensive **refactoring** across the **Chat subsystem** to integrate a `debugOwner` parameter into various chat session acquisition and loading calls, from quick chat to editor inputs and agent sessions. This **new capability** significantly enhances debugging efforts, allowing developers to diagnose potential memory leaks or unexpected model retention within the chat feature, thereby improving its overall **stability and maintainability**.

This commit introduces a **bug fix** within the **CopilotAgent** module, specifically addressing an issue with how it configures `ripgrep`. Previously, the `USE_BUILTIN_RIPGREP` environment variable was incorrectly assigned the string value `'0'`, which could lead to misinterpretation. The change corrects this by setting the variable to `'false'` in `src/vs/platform/agentHost/node/copilot/copilotAgent.ts`. This ensures the **CopilotAgent** accurately determines whether to utilize the built-in `ripgrep` utility, thereby preventing potential search or indexing malfunctions.

This commit introduces the **new capability** to **rename agent host sessions**, allowing users to assign custom, persistent titles to their agent connections for better organization. It significantly enhances the **Agent Host platform**, specifically the `IAgentService` and `ISessionDataService`, by adding **session metadata management** and persistence logic within `sessionDatabase.ts` and `agentSideEffects.ts`. The work involves **refactoring** of session state management to use a `seqAllocator` and updates to the **agent host protocol**, impacting the **remote agent host contribution** and **chat contribution** to display and manage these custom session names. Extensive **testing** was added across various modules to ensure the robustness of session title persistence and related functionalities, improving the overall user experience for agent interactions.

This commit delivers a **bug fix** addressing an issue where **chat agent sessions** would prematurely disappear from the UI. The core problem was an incorrect call to `disposeSession` in `src/vs/workbench/contrib/chat/browser/agentSessions/agentHost/agentHostSessionHandler.ts` when a UI chat session was disposed, leading to the unintended termination of the **agent host backend session**. By removing this erroneous call, the commit ensures that **backend chat sessions** persist correctly, preventing data loss and improving the reliability of chat interactions. A new test case has also been added to verify that disposing a UI chat session no longer incorrectly disposes the backend agent host session.

This commit delivers a **bug fix** addressing an issue where language models were not consistently displayed in the **model picker** for **remote agent host** sessions. Previously, language models might not appear if their provider populated models before registration, causing the `onDidChange` event to be missed. The fix ensures that all language models are **always resolved immediately upon provider registration** within `src/vs/sessions/contrib/remoteAgentHost/browser/remoteAgentHost.contribution.ts`, eliminating this temporal coupling. Additionally, it refines the context key expression in `src/vs/sessions/contrib/copilotChatSessions/browser/copilotChatSessionsActions.ts` to correctly identify remote agent host sessions, improving the reliability of the model selection UI.

This commit delivers **critical bug fixes** to enhance the stability and user experience of **remote agent host sessions**, particularly within **chat interactions**. It addresses **tool call handling** by ensuring the `AgentEventMapper` correctly emits markdown for `message` events that arrive without preceding delta events (e.g., after tool calls complete), and by preventing flickering or duplication of tool call confirmations in the `agentHostSessionHandler`. Furthermore, the `remoteAgentHostSessionsProvider` is updated to prevent **sessions from disappearing from the list** after the first message by implementing pending session tracking. These **maintenance improvements** ensure more reliable agent responses and consistent session management.

This commit implements a crucial **memory optimization** within the **Chat UI rendering** by modifying the `disposeElement` method in `src/vs/workbench/contrib/chat/browser/widget/chatListRenderer.ts`. It now explicitly **clears per-response maps** such as `codeBlocksByResponseId`, `codeBlocksByEditorUri`, `fileTreesByResponseId`, and `focusedFileTreesByResponseId` when chat elements move off-screen. This prevents the unnecessary retention of data for invisible responses, significantly **reducing memory consumption** and improving the overall resource efficiency of the chat feature.

This commit delivers a significant **performance optimization** for the **chat UI**, specifically enhancing the management and rendering of **code blocks**. It introduces a new `KeyedResourcePool` and refines the existing `ResourcePool` to enable more efficient reuse of editor instances for code blocks, incorporating idle item trimming and debouncing. This **maintenance** work improves **resource management** and **rendering efficiency** across various chat content parts, including markdown, tool input/output, and confirmation sub-parts, by intelligently pooling and reusing code block editors. As a result, the chat experience should see improved responsiveness and reduced resource consumption when displaying code. Additionally, this commit updates Copilot chat session actions to support remote agent hosts and refactors model availability logic.

This commit **refactors** the **sessions** and **Copilot Chat sessions** modules by centralizing `RawContextKey` definitions for active session states. It moves keys such as `ActiveSessionProviderIdContext` and `ChatSessionProviderIdContext` from various implementation files into a new shared module, `src/vs/sessions/common/contextkeys.ts`. This **code organization** effort eliminates redundant context key definitions and ensures consistent usage by replacing hardcoded strings with `.key` property access across all consuming components. The change primarily improves the **maintainability** and **consistency** of context key management within the session system.

This commit introduces an **automatic cleanup mechanism** for the **Copilot extension's conversation store**, specifically targeting **disposed chat sessions**. It implements a timed process that removes conversation entries from the LRU cache after 10 minutes of inactivity, significantly improving **resource management** and **memory efficiency**. Accessing a conversation via `getConversation`, `lastConversation`, or `addConversation` effectively resets this cleanup timer, ensuring active sessions are preserved. This **feature** prevents stale conversation data from accumulating and includes new tests for the cleanup logic, alongside a minor **refactoring** of `IConversationStore` registration.

This commit delivers a **bug fix** and **UI refinement** for the **Quick Input** system, preventing the **Command Center** from unnecessarily hiding. Previously, the Command Center would disappear whenever a Quick Pick was active, even if the Quick Pick had been dragged to a custom, non-overlapping position. To address this, the `IQuickInputService` now exposes an `alignment` observable, allowing the **Command Center** to reactively maintain its visibility when the Quick Pick is in a `custom` or `anchored` position. This change improves the user experience by ensuring relevant UI elements remain visible when they do not conflict, alongside several fixes for Quick Pick positioning and drag-and-drop state management.

This commit **refactors** the **codeblock rendering logic** within the **chat and inline chat features** to significantly simplify its implementation. It primarily involves **removing the `CodeBlockModelCollection` dependency** from various rendering components, such as `chatMarkdownContentPart` and `chatListRenderer`. Code blocks now manage their own text models and URIs more directly, streamlining the internal handling of code content. This **refactoring** effort improves maintainability and reduces complexity in how code blocks are displayed, without altering the user-facing experience.

This commit introduces a **new capability** to the **Chat feature**, enabling users to easily copy the final, contiguous markdown content of a chat response. A **"Copy Final Response" context menu action** has been added to the **Chat UI**, which utilizes a new `getFinalResponse` method within the `chatModel` to accurately extract the user-facing output, excluding any intermediate tool calls. This enhancement significantly improves the user experience by providing a dedicated and precise way to retrieve the clean, final response from chat interactions.

This **maintenance** commit **refactors** the **agentHost** server-side dispatch by **removing the `IProtocolSideEffectHandler` interface**, which served as an unnecessary adapter layer. The **`ProtocolServerHandler`** now directly communicates with **`IAgentService`**, centralizing responsibilities for session management, file operations, and authentication within `AgentService` itself. This significantly simplifies the architecture of the **agentHost** subsystem, making the communication flow more direct and efficient. The change eliminates redundant logic, resolves a double-dispatch issue in `dispatchAction`, and ensures extension methods call `IAgentService` directly, leading to a more robust and maintainable design.

This commit performs a significant **refactoring** within the **agent host layer** to standardize the `workingDirectory` parameter. It transitions `IAgentCreateSessionConfig.workingDirectory` and `IAgentSessionMetadata.workingDirectory` from `string` to `URI` across the system. This involves updating **Copilot agent sessions**, **remote agent host sessions**, and the **protocol client communication** to correctly convert between `URI` and `string` representations at various boundaries, including `agenthost://` URIs. This **maintenance** effort improves path handling consistency and robustness, and includes comprehensive **test updates** to reflect these changes, ensuring reliable agent session management.

This commit introduces a **bug fix** to the **Chat** feature, specifically within the `ResolveSymbolsContextAction`. It addresses a **memory leak** by ensuring that the `modelReference` created during symbol resolution is always properly disposed. By wrapping the symbol resolution logic in a `try...finally` block within the `run` method of `chatEditingActions.ts`, this change guarantees resource cleanup. This improvement enhances the overall stability and performance of the **Chat** experience by preventing accumulation of undisposed resources.

This commit performs **maintenance** on the **testing suite** by **skipping a flaky test case** in `src/vs/platform/agentHost/test/node/sessionDatabase.test.ts`. The test, which specifically checks the behavior of `getFileEdits` when provided with an empty array input, was causing intermittent failures. This change improves **test reliability** and prevents unnecessary CI/CD pipeline disruptions. While it temporarily reduces test coverage for this specific edge case, it ensures the overall stability of the automated tests.

This commit performs a **maintenance update** by **bumping the target milestones** for the **notebook** subsystem. This action typically involves updating version numbers or release targets within configuration files, ensuring the `notebook` component aligns with the project's current release schedule and dependency requirements. The change helps manage the lifecycle and compatibility of the `notebook` feature, potentially impacting future development and release planning.

This commit introduces a **new capability** to the **test runner scripts**, enabling them to directly accept bare `.ts` or `.js` file paths as positional arguments. The `test/unit/electron/index.js` script is enhanced to interpret these paths as `--run` values, significantly simplifying the execution of individual or targeted tests. This improvement to the **testing infrastructure** streamlines the developer workflow, particularly for automated agents or specific debugging scenarios, by making test execution more intuitive. Additionally, the `.github/skills/unit-tests/SKILL.md` **documentation is updated** to reflect this new usage, ensuring clarity for developers.