Remove Jupyter suite (5), non-Dracula themes (5), and 7 niche/redundant
extensions: vetur, firefox-debug, import-cost, sourcery, postman,
openvpn, drawio

Skill was a bare .md file instead of a directory with SKILL.md,
causing Claude Code to not detect it

Add CLAUDE.md instruction requiring all SSH commands to include
cd <directory> before service commands, and a PreToolUse hook
script that physically blocks bare SSH commands as a safety net

Critical fixes:
- Fix dot_opencommit.tmpl malformed template leaving empty OCO_API_KEY
- Fix gpg-agent.conf.tmpl using undefined HOMEBREW_PREFIX variable
- Fix run_once_after_install-asdf-plugins.sh.tmpl PATH issue with asdf

Medium priority fixes:
- Fix aliases_all.tmpl upall using hardcoded macOS paths
- Fix executable_git-config.tmpl duplicate AustinHackers entries
- Fix aliases_linuxos.tmpl double slash typo in chezmoi path

Low priority fixes:
- Fix VSCode settings.json.tmpl producing invalid JSON
- Fix aliases_linuxos.tmpl upall using hardcoded brew path

Previously brew shellenv was only evaluated in .zprofile which runs
for login shells only. This caused issues when running 'exec zsh'
or opening new terminal tabs, as Homebrew wouldn't be in PATH.

Now brew shellenv runs in .zshrc for all interactive shells, making
the setup more robust and user-friendly.

mas (Mac App Store CLI) is macOS-only and was failing on Linux
systems with 'macOS is required for this software' error.

Moved from packages.core.brews to packages.darwin.brews so it
only installs on macOS systems.

Homebrew was installing successfully but not being added to PATH
before package installation script ran. This caused all package
installation to be skipped with 'brew not found' error.

Now explicitly adds brew to PATH by evaluating shellenv from known
locations before checking if brew command exists.

- Add Snyk Security Extension auto-generated ignore rule
- Comment out check-json hook in pre-commit config
- Add newline at end of pre-commit config

Fix initialization error on new systems where .personal and .work
data map variables don't exist yet. Changed to use $personal and
$work local template variables instead.

Resolves: "map has no entry for key 'personal'" error during first run