refactor(mcp): ship the tablepro shim in the app bundle

[datlechin]

Why

The command line tool installer wrote /usr/local/bin/tablepro itself, escalating through osascript ... with administrator privileges when the directory was root-owned. That was the app's only admin escalation.

Change

• The tablepro shim ships in the bundle at Contents/SharedSupport/bin/tablepro (Contents/MacOS cannot hold it: the volume is case-insensitive and TablePro is there).
• Settings > General > Command Line shows whether /usr/local/bin/tablepro links to this app and prints the one line to run in Terminal: sudo mkdir -p /usr/local/bin && sudo rm -f /usr/local/bin/tablepro && sudo ln -s <shim> /usr/local/bin/tablepro. rm -f first, so an old link to a directory is replaced rather than written into, and a real directory stops the line.
• Deleted PrivilegedShell and the installer. build-release.sh fails if the shim is missing from the bundle.

Verified

CommandLineShimTests checks the shim is in the test host's bundle and executable, runs the printed link and unlink lines (without sudo) against a temp directory with a quote and a space in the path, over a link to a directory and against a real directory, and reads the status back.

Not in this PR

• The Homebrew cask can add binary "#{appdir}/TablePro.app/Contents/SharedSupport/bin/tablepro".
• A tablepro script installed by an earlier version keeps working; Settings reports it as another file until relinked.

Docs: TableProApp/docs#7