Fix GNOME extension package bootstrap on Ubuntu

[timrichardson]

Fixes #39

Summary

• stop installing the nonexistent gnome-shell-extension-tool apt package on GNOME
• install gnome-shell only when gnome-extensions is missing and apt can provide it
• update the missing-CLI guidance to name the actual provider path instead of the removed package

Verification

• bash -n install.sh
• git diff --check
• ./install.sh --skip-system-deps --skip-doctor

[gemini-code-assist]

Code Review

This pull request updates the install.sh script to check for and install gnome-shell instead of gnome-shell-extension-tool when the gnome-extensions CLI is missing on GNOME desktop environments, and updates the corresponding warning message. The review feedback suggests allowing apt-get update to fail gracefully with a warning instead of aborting the script, which improves the resilience of the installation process.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[timrichardson]

Clarification after checking Ubuntu 26.04 apt metadata:

gnome-shell-extension-manager is available on Ubuntu 26.04, but it is a separate GUI application for browsing, installing, and configuring GNOME Shell extensions. It is not the package this installer needs.

The installer needs the gnome-extensions CLI so it can run commands like gnome-extensions pack, install, and enable. On Ubuntu 26.04 that CLI is provided by the gnome-shell package:

/usr/bin/gnome-extensions
gnome-shell: /usr/bin/gnome-extensions

The package that failed in the installer, gnome-shell-extension-tool, does not exist in Ubuntu 26.04. So the fix should avoid that package name; installing gnome-shell-extension-manager would add an unnecessary GUI dependency and would not be the right CLI-specific dependency.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[avifenesh]

Looks good. I validated this against the current Ubuntu 26.04 package state: the failing package name is not installable, while gnome-shell provides the gnome-extensions CLI the installer actually needs. The apt/GNOME branch behaves correctly in mocked installer runs, and local validation passed. The apt-get update resilience suggestion is pre-existing installer hardening, not a blocker for this fix.

[avifenesh]

@timrichardson Thanks a lot!