## Context

The editor tab's read-only controls used "File" terminology in their
tooltips and the tab context menu ("Make File Read-Only", "Locked File",
"Read-Only File", etc.). This was misleading in two ways: the option
also appears on unsaved and non-file tabs that have no file on disk, and
the toggle only controls whether the buffer is editable in the editor,
it does not change filesystem permissions. This renames the labels to
lock/unlock "Tab" language, matching the lock icon shown when the tab is
toggled.

Closes #60079.

Behavior after the change :

[Screencast from 2026-07-17
15-35-30.webm](https://github.com/user-attachments/assets/5fb018cb-515f-449c-a57e-0c0bead250bd)


## How to Review

1 file changed:

**crates/workspace/src/pane.rs**
Renames three sets of user-facing strings, all pure text changes with no
behavior change. The read-only toggle button tooltips become "Unlock
Tab" / "This will make this tab editable" and "Locked Tab" / "This tab
is read-only". The tab tooltip meta label becomes "Read-Only Tab". The
context menu entry, whose label already depends on
`capability.editable()`, becomes "Lock Tab for Editing" (when currently
editable) and "Unlock Tab for Editing" (when currently read-only); the
click handler still calls `toggle_read_only`, so the mapping from label
to action is preserved.

## Self-Review Checklist

- [x] I've reviewed my own diff for quality, security, and reliability
- [ ] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the UI/UX checklist
- [ ] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Improved read-only tab controls to use "Tab" instead of "File" in
tooltips and the tab context menu, since the toggle affects editability
in the editor rather than filesystem permissions.

---------

Co-authored-by: Nathan Sobo <nathan@zed.dev>