feat(repo-sync): one local tree for every repo reachable on your forges

bin/repo-sync ports the Alphalink dotfiles repo/repo-reset zsh functions to
bash + zsh on Linux and macOS, for several forges at once: GitLab, GitHub
(+GHES), Gitea/Forgejo, Bitbucket Cloud, via curl + jq (no per-forge CLI).
Tokens live in ~/.config/repos/forges.conf (0600, parsed line by line, never
tracked), written by `repo-sync add`. Cache ~/.cache/repos/list refreshed
at most once a day (mkdir lock: flock is not on macOS), same namespace/project
on two forges kept once, archived and mirrors skipped. Layout
~/repos/<namespace with / as @>/<project>.

rc files: `repo <project> [namespace]` clones on demand and cd's, with
completion (bash compgen, zsh _describe), background refresh at shell start.
install.sh: jq in the apt and brew lists, chmod repo-sync.

Verified: shellcheck + bash -n, zsh -n; stub-curl harness over the four forges
(pagination, dedup, auth headers, lock, stale cache, path/clone); live GitLab
refresh (139 projects, 3s).

CLAUDE.md

@@ -26,6 +26,8 @@ gitconfig                        user-scope ~/.gitconfig template, @USER@/@EMAIL
 tmux.conf                        tmux config (vi keys, tpm plugins) → ~/.config/tmux/tmux.conf, both OSes (tmux ≥ 3.1)
 zsh/{zshrc-osx,bchanot.zsh-theme}  macOS zsh option: oh-my-zsh zshrc + theme porting the bash prompt
 bin/{dt,dtach-router,claude-provider}   CLI scripts deployed to ~/.local/bin
+bin/repo-sync                    multi-forge repo tree (gitlab/github/gitea/bitbucket cloud) → ~/repos, daily cache;
+                                 tokens in ~/.config/repos/forges.conf (0600, never tracked); `repo` fn in the rc files
 etc/profile.d/disk-usage-warning.sh     login-time low-disk warning → /etc/profile.d (Linux only)
 etc/tmpfiles.d/tmp.conf                 disk-backed /tmp cleanup rules (offer: /tmp on disk)
 etc/systemd/ssh.service.d/override.conf sshd OOM-exempt drop-in (offer: SSH memory guard)