fix: resolve shell startup errors and streamline tool management

- Guard brew shellenv in fish config with test -x for Linux compat
- Pin Python to 3.13 with compile=true (freethreaded builds broken)
- Pin neovim, go, terraform, aws-cli, cmake, dotnet-ef to stable versions
- Remove hugo and gdu from mise (unused / broken upstream)
- Comment out pipx-backed tools (mise can't find uvx when self-managed)
- Move mise [settings] above [tools] with pipx.uvx=true
- Fix dnf group name for dnf5 (development-tools lowercase)
- Remove vendored fzf binary (now managed by mise)
- Simplify Dotbot: force-relink mise config, targeted ~/.local clean,
  remove fzf custom linking (now via standard ~/.config/ glob)
- Fix lint gate hook to find yarn via mise shims

config/fish/config.fish

@@ -52,4 +52,4 @@ source ~/.orbstack/shell/init2.fish 2>/dev/null || :
 if status is-interactive; and not set -q GITHUB_TOKEN
     echo "Warning: GITHUB_TOKEN is not set" >&2
 end
-eval "$(/opt/homebrew/bin/brew shellenv fish)"
+test -x /opt/homebrew/bin/brew; and eval "$(/opt/homebrew/bin/brew shellenv fish)"