Add "Open in…" dropdown for selected item (Finder, Terminal, VS Code, Cursor, Claude Desktop, ChatGPT, Codex, copy path)

[trieloff]

Summary

Add an "Open in…" dropdown to the content browser for the selected item, offering quick handoff to external tools:

• Finder — reveal the synced file/folder
• Terminal — open at the item's local directory
• VS Code — open the file/folder
• Cursor — open the file/folder
• Claude Desktop
• ChatGPT
• Codex
• Copy path — copy the path to the clipboard

Why

Once an item is selected (and synced locally), the natural next step is often to open it somewhere else — edit it in an editor, poke at it in a terminal, or hand it to an AI tool. Today there's no path out of the app; you have to find the synced folder manually.

Suggested placement

Alongside the existing actions in the file-tree panel header (renderPanelHeader in src/renderer/file-tree.js, next to Sync selected… / Review changes…), driven by state.tree.selectedPaths. A single split/dropdown button keeps the header uncluttered.

Implementation notes / open questions

• Local-path dependency: Finder, Terminal, VS Code, Cursor, and Codex all need a local filesystem path, which only exists after the item has been synced. We'll need to map the selected DA path → local path (via the sync-folder store) and either disable those targets or trigger a sync first when no local copy exists. Copy path could offer either the DA path or the local path.
• App detection: only show targets for apps that are actually installed (e.g. probe known bundle IDs / app paths on macOS) rather than listing everything.
• Launch mechanism: Finder/Terminal via shell.openPath / open; editors via their CLI (code, cursor) or bundle ID; AI tools via their URL scheme or app handoff (needs investigation per app).
• macOS-first is fine given the app is Apple-Silicon-only today.

Acceptance criteria

• "Open in…" control appears when an item is selected
• Targets that require a local file are disabled (or trigger a sync) when the item isn't synced
• Only installed apps are listed
• "Copy path" copies a sensible path to the clipboard