Add start endpoint and decouple IPC from tunnel lifecycle

[atavism]

No description provided.

[Copilot]

Pull Request Overview

This PR decouples the IPC server lifecycle from the tunnel lifecycle by introducing a new start endpoint and moving IPC initialization to a separate function. The IPC server now runs independently and can start/stop tunnel services on demand.

• Removed IPC server initialization from tunnel establishment
• Added new start endpoint to the IPC server for on-demand tunnel creation
• Introduced InitIPC function to manage long-lived IPC server lifecycle

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
vpn/tunnel.go	Removed IPC server initialization and cleanup from tunnel establishment
vpn/ipc/server.go	Added start endpoint handler and StartFn callback mechanism
vpn/ipc/endpoints.go	Added new start service endpoint constant
vpn/ipc.go	New file containing InitIPC function and tunnel startup logic

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[atavism]

@garmr-ulfr @WendelHime I'm testing these changes today on Windows but feel free to take a look!

[garmr-ulfr]

LGTM

[atavism]

Thanks for the review, @garmr-ulfr!