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).

README.md

@@ -36,6 +36,7 @@ curl -fsSL https://git.bchanot.fr/bchanot/config/raw/branch/master/remote-instal
 | `bin/dt`             | dtach session manager for claude-in-dtach sessions.            |
 | `bin/dtach-router`   | Dashboard to resume dtach sessions, shown at the start of every interactive shell (wired into `~/.bashrc` by the installer). |
 | `bin/claude-provider`| Switch Claude Code between Anthropic and OpenRouter.           |
+| `bin/repo-sync`      | One local tree (`~/repos`) for every repository reachable on your forges (GitLab, GitHub, Gitea/Forgejo, Bitbucket Cloud), daily cache, `repo <project>` shell function to jump into one. |
 | `etc/profile.d/disk-usage-warning.sh` | Login-time warning (bold red) when `/` or `/home` cross 85% usage. Deployed to `/etc/profile.d/` on Linux. |
 
 ## Install
@@ -121,6 +122,12 @@ Deployed to `~/.local/bin` (the deployed bashrc adds this dir to `PATH`):
   ```sh
   export OPENROUTER_API_KEY="<your-openrouter-key>"
   ```
+- **`repo-sync`** — one local tree for every git repository you can reach on your forges, same layout as the Alphalink `repo` zsh function: `~/repos/<namespace with / as @>/<project>` (`REPOS_DIR` overrides). Needs `jq`, `curl`, `git`.
+  - `repo-sync add` registers a forge (type `gitlab|github|gitea|bitbucket`, host, token asked on the terminal) in **`~/.config/repos/forges.conf`** (mode 0600, parsed line by line, never tracked). Run it once per access you have. GitHub Enterprise and self-hosted GitLab/Gitea work by host; Bitbucket is Cloud only (Atlassian email + API token).
+  - `repo-sync refresh` rebuilds the project list in `~/.cache/repos/list` when it is older than a day (`--force` to redo it now). The deployed rc files run it in the background at shell start, so the list is fresh at most once per day without a cron.
+  - `repo-sync list|tree` shows the projects; `repo-sync clone [--filter REGEX] [--pull] [--dry-run] [--https]` clones everything missing.
+  - `repo <project> [namespace]` (shell function, bash and zsh, with completion) clones on demand and `cd`s into it. The token only lists projects; clones use ssh unless `--https`.
+  - The same `namespace/project` on two forges is kept once, from the first section of `forges.conf`. Archived projects and mirrors are skipped.
 
 ## Requirements