Review Agent (Code Review - Uncommitted Changes) does not apply github.copilot.chat.reviewSelection.instructions

- Copilot Chat Extension Version: 0.57.0
- VS Code Version: 1.129.1 (Commit: 8a7abeba6e03ea3af87bfbce9a1b7e48fed567b8, Electron: 42.6.0, Node.js: 24.18.0)
- OS Version: Windows 11
- Feature (e.g. agent/edit/ask mode): Code Review - Uncommitted Changes (Review Agent)
- Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): N/A
- Logs:
```
Copilot Chat: 0.57.0
Copilot preview features are disabled by organizational policy.
[github review agent] request id: ...
```
No log entries indicating that repository instruction files are loaded by the Review Agent.

Steps to Reproduce:

1. Configure `github.copilot.chat.reviewSelection.instructions` in VS Code settings with instruction files and/or inline text, e.g.:
```json
{
"github.copilot.chat.reviewSelection.instructions": [
{ "file": ".github/copilot-instructions.md" },
{ "file": ".github/instructions/angular-jest-review.instructions.md" },
{ "file": ".github/instructions/sonar-review.instructions.md" },
{ "text": "During code review, always validate behavioral correctness, edge-case handling, Sonar-style issue patterns (BUG, VULNERABILITY, CODE_SMELL), and whether changed logic has focused Jest tests." }
]
}
```
2. Create valid `.instructions.md` files in `.github/instructions/` (with `applyTo` frontmatter, e.g. `applyTo: "src/**/*.ts,src/**/*.html"`). Confirm these files are loaded correctly by Copilot Chat.
3. Modify a TypeScript or HTML file.
4. Open the Source Control panel.
5. Click **Code Review - Uncommitted Changes**.
6. Wait for the review to complete.

**Expected Behavior:**

The review should include the configured repository instructions, such as:
- Angular review guidance
- Jest test validation
- Sonar-style issue detection
- Custom review rules defined in the instruction files

These instructions should be applied consistently across all review experiences (Copilot Chat, Review Selection, and Code Review - Uncommitted Changes).

**Actual Behavior:**

The generated review does not use any of the configured instruction files or inline instruction text.

Evidence:
- ✅ Copilot Chat honors `github.copilot.chat.reviewSelection.instructions`
- ✅ Review Selection honors `github.copilot.chat.reviewSelection.instructions`
- ❌ **Code Review - Uncommitted Changes does not**

Adding an obvious marker text (e.g. `"Always begin the review with 'Instruction Loaded'"`) to the instructions confirms the Review Agent does not include the configured instructions — the marker never appears in the review output.

**Additional Context:**

- License: Copilot for Business
- Copilot preview features are disabled by organizational policy.
- The instruction files are valid `.instructions.md` files with proper YAML frontmatter (`name`, `description`, `applyTo` fields).
- The issue is reproducible consistently across multiple sessions and file types.

**Impact:**

Repository instruction files are used to enforce Angular best practices, Jest testing requirements, SonarQube-style review rules, accessibility checks, and organization-specific review standards. These work correctly in Copilot Chat but cannot currently be leveraged by the automated Review Agent, leading to inconsistent review quality.

**Questions:**
1. Is this expected behavior?
2. Does the Review Agent currently support `github.copilot.chat.reviewSelection.instructions`?
3. If not, is there a separate mechanism for providing custom review instructions to the Review Agent?
4. Is this limitation related to Copilot for Business or disabled preview features?

**Suggested Enhancement:**

Support repository instruction files (or provide an equivalent configuration) for the **Code Review - Uncommitted Changes** Review Agent so that review behavior is consistent across Copilot Chat, Review Selection, Review Agent (Uncommitted Changes), and Pull Request Reviews.