feat(desktop): open remote projects in Zed

[jln13x]

What changed

Remote environments hide Zed from the Open menu even when it is installed on the viewing Mac. This adds Zed to remote editor discovery and generates its SSH deep links. For example, opening a worktree on the zeus SSH alias now hands zed://ssh/zeus/home/agent/code/project to the local Zed application.

Adapted from pingdotgg/t3code#8866, with additional regression tests for protocol discovery, CLI fallback, malformed links, and worktree paths containing spaces, #, and %. The fork inventory records this as a temporary integration to retire when upstream support lands.

Why

Zed uses a different SSH URL format from VS Code. Shared editor metadata now supplies that format to the URL builder and desktop URL validation. Desktop discovery checks registered OS handlers before CLI availability, which covers Finder-launched apps without Zed on PATH. Browser fallback offers VS Code and Zed.

The toolbar button, editor dropdown, and favorite-editor shortcut use the same remote-open path. This applies to web and desktop and is provider-independent. Mobile has no corresponding desktop-editor picker. Server behavior, RPC schemas, and stored data are unchanged, so remote upstream servers remain compatible.

Validation

• 59 tests passed across remoteOpen.test.ts, ElectronShell.test.ts, window.test.ts, and DesktopWindow.test.ts. The nine window IPC tests passed again after fixing their Effect test context.
• Scoped typechecks passed for web, desktop, and contracts.
• Formatting, targeted lint, and git diff --check passed.
• Real browser and macOS-to-Zed launch verification remain pending. No installed application was replaced.

UI changes

Draft pending the fork's own before/after screenshots and launch verification. Browser permission was requested under AGENTS.md and has not yet been granted.

The upstream implementation includes reference screenshots and a recording; these are upstream evidence, not verification of this fork build.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for UI changes
• I included a video for interaction changes

Implemented with GPT-6 via Codex.