Increase the default timeout for downloading the Copilot CLI tarball from 100s
(the HttpClient default) to 600s (10 minutes) to handle slow or unreliable
network conditions.

The timeout is configurable via the CopilotCliDownloadTimeout MSBuild property.

Fixes #451

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

Add MSBuild property CopilotSkipCliDownload that when set to true skips
automatic download and bundling of the Copilot CLI binary. This is useful
for users who install the CLI separately (e.g., via npm or a package manager)
and want to avoid the build-time download.

When skipped, users must ensure COPILOT_CLI_PATH or the CliPath option
points to a valid CLI installation at runtime.

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

* Use MCP direct env var mode in Node SDK

* Equivalent fixes for other languages

* Update @github/copilot to 0.0.411-1 and regenerate SDKs

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

* Fix Python lint errors (line too long)

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

* Add normalizer to strip <reminder> tags from user messages

The CLI now injects dynamic <reminder> tags with SQL table state into user
messages. These tags vary based on runtime state and should not affect
snapshot matching.

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

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