Prevent active file context in locked coding agent chat sessions

[Copilot]

When opening a Coding Agent Chat in a new window, the active file was incorrectly being included as context. This happened because the ChatImplicitContextContribution automatically adds active file context to all chat widgets without checking if they are locked to a coding agent.

The Problem

The implicit context system would add the currently active file as context to any chat widget, including those that are locked to coding agents. This is undesirable behavior because coding agent sessions should operate independently without automatically inheriting context from the user's current workspace state.

The Solution

Added a check for widget.isLockedToCodingAgent in the ChatImplicitContextContribution.updateImplicitContext() method. Now, when a chat widget is locked to a coding agent, no implicit context (active file) will be set.

The change is minimal and surgical - only one condition was added to the existing logic:

if ((setting === 'always' || setting === 'first' && isFirstInteraction) && !isPromptFile && !widget.isLockedToCodingAgent) {
    widget.input.implicitContext.setValue(newValue, isSelection, languageId);
} else {
    widget.input.implicitContext.setValue(undefined, false, undefined);
}

This preserves all existing functionality for normal chat sessions while ensuring that locked coding agent sessions don't receive unwanted active file context.

Fixes #263505.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• electronjs.org
  • Triggering command: node-gyp (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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