Dmitriy Vasyura

agentHost: implement resource watch and filesystem operations Extend the AHP protocol with full filesystem operation support: - Add resourceResolve, resourceMkdir, and resourceCopy methods to make efficient, single-round-trip filesystem operations - Implement createResourceWatch with lazy watcher materialization (FS watcher only created on first subscribe) - Add 30-second grace period and replay buffer for watch channel unsubscribe to support reconnections - Surface watch setup errors via onDidWatchError event for proper error propagation - Make resourceCopy, resourceResolve, resourceMkdir required (not optional) in IRemoteFilesystemConnection contract - Extend both client→server and server→client (reverse-RPC) channels with all new methods - Add comprehensive unit tests: watch lifecycle, error handling, includes pattern forwarding, copy/resolve/mkdir operations - All tests passing (37 total, 7 new), TypeScript compilation clean, layer validation clean

Add Tools to Chat Customizations (#322620)

Fix model selection issues when switching session types (#320036)

Refine MCP registry-only enforcement (#328482) * Refine MCP registry-only enforcement Use verified gallery metadata as the membership proof, preserve trusted install sources, coalesce registry synchronization, and add workbench lifecycle coverage. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Address MCP registry enforcement feedback Reject stale gallery provenance across registry changes, order concurrent profile reloads, propagate update metadata sources, and add race regression coverage. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Enable BYOK in air-gapped scenarios/without GitHub auth (#317428) Air-gapped BYOK: enable chat and some other AI functionality when user is not authenticated (with or without utility models enabled).

Streamline update mode configuration and handling (#323206) Enables changing update mode without restart, allowing policy updates to cancel an in-progress update.

Refactor `galleryItemRenderer` into reusable component and add extension tools details (#322879) Refactored galleryItemRenderer into a component shared between MCP, Plugins and Tools views. Added Extension tools details pane to view tools provided by an extension from the Tools view. Fixed an issue in MCP view where installed items were rendered incorrectly

Move Update button to the right-most position in the title bar (#329239) * Move Update button to the right-most position in the title bar * Fix title bar overflow edge cases Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Avoid leaving detached DOM elements in Getting Started (#319128)

Handle opened and unsaved documents as attachments for Agent Host/Copilot CLI (#321591)

Filter out agent host-owned sessions from CLI session list to avoid duplicates (#320188)

Add Tools tree keyboard navigation, fix focus outline cut-off at widget edges (#323984) * Add Tools tree keyboard navigation, fix focus outline cut-off at widget edges * PR feedback

Fix session list hovers to avoid warnings and updates while a hover is active (#321596)

Perf: Dedupe tool-definition JSON across telemetry/OTel sites (#318477) * perf(copilot): dedupe tool-definition JSON across telemetry/OTel sites Each LLM round previously serialized the tool list multiple times (OTel inference span, OTel agent span, 'tools_available' event, GH 'request.options.tools' enhanced telemetry, and per-key 'request.option.tools' property), producing several independent multi-MB strings retained by buffered spans and telemetry queues. Add stringifyToolDefinitionsForOTel and stringifyToolsRawForTelemetry in messageFormatters: a WeakMap by-reference cache plus a single-slot content intern so identical tool lists across consecutive agent rounds collapse to one string instance. Wire all producer sites (chatMLFetcher GH telemetry + Object.entries loops, toolCallingLoop agent span and tools_available event, anthropic/gemini byok providers, genAiEvents inference event) through the helpers. * fix: leave Object.entries(request) telemetry loop untouched Those properties are sent synchronously and released; they weren't among the retained copies. The other helper sites still dedupe the long-lived strings. * perf: route tools through memoized helper in Object.entries loops with JSON.stringify fallback to preserve empty-array byte equality * Simplify comment * PR feedback

Fix late Agent Host session type registration (#328337) Subscribe to session type changes before creating a new-session draft and replay changes that arrive while creation is in flight. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Propagate context window options from Copilot models to the picker (#320905)

Fix language model event issues (#319097) * Fix selectChatModels API * Prevent feedback loop through onChatModelsChange event Co-authored-by: Copilot <copilot@github.com> --------- Co-authored-by: Copilot <copilot@github.com>

Fix race condition involving eager createSession in chat sessions pro… (#321526) * Fix race condition involving eager createSession in chat sessions provider

Improve offline BYOK UI state management (#316579) Co-authored-by: Copilot <copilot@github.com>

Fix snippet choice trapping Shift+Tab navigation (#316822) When a snippet choice tab stop was active, the suggest widget's Shift+Tab binding (acceptAlternativeSelectedSuggestion, weight EditorContrib+90) outranked the snippet's jumpToPrevSnippetPlaceholder (weight EditorContrib+30), so Shift+Tab could not navigate back to the previous tab stop. Add an InSnippetChoice context key and register a higher-weight Shift+Tab keybinding rule for jumpToPrevSnippetPlaceholder that activates only when a snippet choice is active. Fixes #236489