feat(proxy): allow socks proxy for the notifications

[ASLanin]

Summary

In this pull request, the following changes are made:

Parsing NOTIFICATION_PROXY and notification_proxy env for known socks protocols and set appropriate agent.

in two words:
Simple else if added to the notification_proxy variable checking.
To be honest I tested on the socks5 only, relying on socks-proxy-agent package that way.

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Screenshots for Visual Changes

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[github-actions]

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[Copilot]

Pull request overview

Adds SOCKS proxy support for notification HTTP requests by extending the existing NOTIFICATION_PROXY / notification_proxy env-based proxy handling in the backend notification provider.

Changes:

• Import SocksProxyAgent for SOCKS proxy support.
• Extend getAxiosConfigWithProxy() to detect SOCKS protocols (socks/socks4/socks5/socks5h) and apply the appropriate agent.

[Copilot]

The list of supported SOCKS protocols is hard-coded here, while similar protocol support is also maintained in server/proxy.js (Proxy.SUPPORTED_PROXY_PROTOCOLS). This duplication can drift over time (e.g., if supported proxy protocols are expanded/renamed in one place but not the other). Consider centralizing the supported-protocol mapping (or deriving the ...: URL protocol list from the shared constant) so notification proxy handling stays consistent with the rest of the proxy implementation.

[Copilot]

SOCKS proxy support is newly added here, but there are no backend tests asserting that getAxiosConfigWithProxy() configures the correct agent for socks/socks4/socks5/socks5h URLs (and that existing http/https behavior is unchanged). Adding a small unit test that sets process.env.NOTIFICATION_PROXY to a SOCKS URL and verifies axiosConfig.httpAgent/httpsAgent are instances of the expected agent would help prevent regressions.

[CommanderStorm]

Lgtm

[github-actions]

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