fix(publish): CSS sidebar is off on smaller screens like iPad

[eleweek]

fix(publish): CSS sidebar is off on smaller screens like iPad

Fixes #2290 by making sure we never actually subtract from the minimum 200px width

Testing

• Write Tests
• Confirm existing tests pass
• Confirm manual testing
• If your tests changes an existing snapshot, make sure that snapshots are updated
• If you are adding a new language feature (graphically visible in VS Code/preview/publishing), make sure that it is included in the test workspace

Docs

• if your change reflects documentation changes, also submit a PR to dendron-site and mention the doc PR link in your current PR

Analytics

• if you are adding analytics related changes, make sure the Telemetry docs are updated

[hikchoi]

We should re-open the linked issue since this won't be released until next week, and follow [[After Release|dendron://dendron.handbook/templates.weekly-planning.user#after-release]] after v80 ships.