Fix get_changed_files sourceControlState ignored (#269452)

[pedrocostadev]

Problem

get_changed_files returns stale/empty results for unstaged changes because the changes object in RepoContextImpl captures array references at construction time rather than fetching fresh values.

When the Git extension updates repo state, it creates NEW arrays. The changes object still references the OLD arrays.

Root Cause

File: src/platform/git/vscode/gitServiceImpl.ts

// Before: Static object - arrays captured once
public readonly changes = {
    mergeChanges: this._repo.state.mergeChanges,
    indexChanges: this._repo.state.indexChanges,
    workingTree: this._repo.state.workingTreeChanges,
    untrackedChanges: this._repo.state.untrackedChanges
};

Fix

Convert changes from a static property to a getter so fresh values are fetched from _repo.state each access:

// After: Getter fetches fresh values each access
public get changes() {
    return {
        mergeChanges: this._repo.state.mergeChanges,
        indexChanges: this._repo.state.indexChanges,
        workingTree: this._repo.state.workingTreeChanges,
        untrackedChanges: this._repo.state.untrackedChanges
    };
}

Testing

• TypeScript compiles without errors
• All git-related unit tests pass (npm run test:unit -- src/platform/git)
• Interface RepoContext unchanged (getter is compatible with readonly property)

Fixes microsoft/vscode#269452

[Copilot]

Pull request overview

This PR fixes a bug where get_changed_files returns stale results for unstaged changes because the changes property was capturing array references at construction time instead of fetching fresh values from the Git repository state.

Changes:

• Convert changes from a static readonly property to a getter in RepoContextImpl to ensure fresh repository state is retrieved on each access