Ensures the search subagent's parentChatSessionId is always set by
falling back to the conversation's sessionId when the capturing token's
chatSessionId is unavailable. Without this fallback the search subagent
spans lacked PARENT_CHAT_SESSION_ID and were uploaded as independent
cloud sessions instead of folding into the parent.

Follow-up fix for #318463.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* test: Add BYOK retry regression coverage

 - add BYOK Responses retry regression for ignored stateful marker
 - preserve non-ZDR initial request and ZDR guard coverage

* fix: Preserve BYOK retry marker suppression

 - keep explicit ignoreStatefulMarker on non-ZDR retries
 - retain existing ZDR and shared Responses behavior

* chore: Clarify BYOK retry comment

- clarify initial-request default vs retry override
- point retry-time override at parent retry flow

* fix: Preserve explicit BYOK marker override

- keep caller-supplied ignoreStatefulMarker values
- add makeChatRequest2 regression coverage

* test: Fix BYOK response fixtures

- add missing ChatResponse success fields
- keep makeChatRequest2 regression tests typed

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Co-authored-by: Vritant Bhardwaj <vritoku@gmail.com>

…8503)

* Chronicle: handle undefined CapturingToken in execution_subagent

* minor update

…tries in model picker

Co-authored-by: vs-code-engineering[bot] <vs-code-engineering[bot]@users.noreply.github.com>

…copilot-linuxmusl` packages (#318490)

Co-authored-by: vs-code-engineering[bot] <vs-code-engineering[bot]@users.noreply.github.com>

…#318479)

* Add /chronicle:improve prompt for data-driven instructions refinement

* Address review feedback: typo fix and instructions file clarity

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Chat: OTel enrichment for Claude agent sessions

* 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

…oid race with killForceful timer

Co-authored-by: vritant24 <13074644+vritant24@users.noreply.github.com>

…on with specific Agent in Agent Window (#318506)

…() to avoid race with killForceful timer"

This reverts commit 0baa8cd.

…models-issue

Prevent signed-out users from seeing GitHub Copilot upgrade recommendations

* Fix chat notification outline to match chat input focus ring

Co-authored-by: Copilot <copilot@github.com>

* PR feedback

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Co-authored-by: Copilot <copilot@github.com>