Agent init cannot refresh a locked telemetry hook and reports an unclear access error

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

On Windows, `aspire agent init` cannot refresh `ASPIRE_HOME\hooks\track-telemetry.ps1` when the existing script is temporarily open without delete/write sharing, which can happen while the telemetry hook is executing.

The installer writes the updated content to a sibling `track-telemetry.ps1.tmp-*` file, but the atomic replacement fails. The command then displays only:

```text
Access to the path is denied.
```

It immediately follows that with `Agent environment configuration complete.` and exits with code `0`. The existing hook remains stale, the temporary file is stranded, and the message does not identify the file, operation, or affected client.

This reproduces on current `main` at `ff714afede575552c75d3de9584a643d98b6690e` with CLI version `13.6.0-dev`.

### Expected Behavior

Refreshing telemetry hooks should tolerate a short-lived lock, for example with a bounded retry or safe deferred replacement. If the refresh still cannot complete, the CLI should identify the affected hook path/client and should clean up the sibling temporary file rather than reporting only a generic access-denied message followed by an unqualified success message.

### Steps To Reproduce

Build the CLI from current `main`, then run the following from PowerShell in a scratch directory. This uses isolated Aspire and Copilot homes.

```powershell
$workspace = Join-Path $PWD "workspace"
$env:ASPIRE_HOME = Join-Path $PWD "aspire-home"
$env:COPILOT_HOME = Join-Path $PWD "copilot-home"
$env:TERM_PROGRAM = "vscode"

New-Item -ItemType Directory -Force `
(Join-Path $workspace ".vscode"), `
(Join-Path $env:ASPIRE_HOME "hooks"), `
$env:COPILOT_HOME | Out-Null

$hook = Join-Path $env:ASPIRE_HOME "hooks\track-telemetry.ps1"
Set-Content -LiteralPath $hook -Value "# stale hook content"

# Allow reads but deny writes/deletion, simulating a concurrently executing hook.
$lock = [System.IO.File]::Open(
$hook,
[System.IO.FileMode]::Open,
[System.IO.FileAccess]::Read,
[System.IO.FileShare]::Read)

try {
aspire agent init `
--workspace-root $workspace `
--skill-locations none `
--skills none `
--non-interactive `
--nologo
}
finally {
$lock.Dispose()
}

$LASTEXITCODE
Get-ChildItem -LiteralPath (Join-Path $env:ASPIRE_HOME "hooks") -Filter "track-telemetry.ps1.tmp-*"
```

Observed output:

```text
🤖 Detecting agent environments...
Access to the path is denied.
✅ Agent environment configuration complete.
```

The exit code is `0`, and `track-telemetry.ps1.tmp-*` remains in the hooks directory.

### Exceptions (if any)

No exception type, stack trace, path, or client name is surfaced to the user. The access-denied text comes from the broad best-effort catch around `ITelemetryHookConfigurator.ConfigureAsync`.

### Aspire doctor output

N/A — the failure is reproduced by locking the existing telemetry hook during refresh and is not dependent on Aspire environment health.

### Anything else?

- **Environment:** Windows ARM64, PowerShell, .NET 10
- **Aspire CLI:** `13.6.0-dev`, main commit `ff714afede575552c75d3de9584a643d98b6690e`
- `TelemetryHookInstaller.WriteIfChangedAsync` writes a sibling temp file and then calls `File.Move(tempPath, path, overwrite: true)` without retry or cleanup when replacement fails.
- The failure occurs before the per-client write-result handling in `TelemetryHookConfigurator`, so `AgentInitCommand.ConfigureTelemetryHooksAsync` catches the exception and displays only `ex.Message`.

Start with TelemetryHookInstaller.WriteIfChangedAsync and its File.Move call, then trace how failures flow through TelemetryHookConfigurator and AgentInitCommand.ConfigureTelemetryHooksAsync. Run the supplied PowerShell reproduction; done means locked-hook refreshes are handled within a bounded policy, temporary files are cleaned up, and an incomplete refresh reports the affected hook and client without an unqualified success.

Written by the indexing model from the issue text.