Add an “Open file…” entry in OK Desktop for temporary single-file sessions

[kinpoe-ray]

Summary

The CLI supports opening a standalone Markdown file directly in OK Desktop:

ok open /absolute/path/to/file.md

This creates/uses a temporary session and does not require initializing the file's containing directory as an OpenKnowledge project.

However, OK Desktop 0.35.0-beta.4 does not expose an equivalent Open file… action in its File menu. The visible menu provides Open folder…, which leads users toward project setup rather than the safe single-file preview flow.

Verified current UI

On macOS, the OK Desktop File menu currently contains entries including:

New file
New folder
New from template…
Recent project
New project…
Switch project…
Open folder…
New worktree…
Switch worktree…
...

There is no Open file… entry.

The bundled CLI explicitly documents:

ok open <name>

Open a doc, folder, or skill in the OK Desktop app.
Docs and folders are auto-detected.

User problem

A user who wants to preview an arbitrary Markdown file from outside an initialized project naturally looks in OK Desktop. Because only Open folder… is visible, they may select the containing folder instead.

For an ordinary folder, Desktop can then show “Setup OpenKnowledge in this folder?”. Clicking the primary Setup action changes the folder into a persistent OK project and may even create an unwanted parent project above existing child projects.

The safe feature already exists through the CLI, but it is not discoverable in Desktop.

Expected behavior

OK Desktop should expose the same standalone-file flow as ok open /path/file.md through a native file picker.

Suggested entry:

File → Open file…    ⇧⌘O (or another suitable shortcut)

Selecting a .md or .mdx file should:

1. Open it in the existing temporary/single-file session behavior.
2. Avoid creating .ok in the source directory.
3. Clearly label the window/session as a standalone file or temporary session.
4. Offer a separate, explicit action later if the user wants to convert the containing folder into an OK project.

Additional UX suggestions

• Add Open file… to Project Navigator near Open folder….
• Allow dropping a .md/.mdx file onto the app/window to invoke the same flow.
• Support Finder Open With → OpenKnowledge consistently.
• Explain the distinction in the UI:
  • Open file — preview/edit one file without project setup
  • Open folder — open or initialize a persistent project
• Do not route single-file intent through the folder Setup dialog.

Environment

• OK Desktop 0.35.0-beta.4
• macOS arm64