refactor(scripts/post-install): consolidate gitrepos.sh and harden the script

gitrepos.sh did the same `~/.dotfiles` / `~/.emacs.d` remote swap that
post-install.sh already had, plus a `git pull --set-upstream origin main`
follow-on that post-install was missing. I folded the pull into the
post-install remote-rewrite block and dropped gitrepos.sh.

While in the file, I also:

- Quoted every variable (`"$logfile"`, `"$HOME"` paths, `"$(whoami)"`).
- Sent the remote-rewrite block to the log file like the other blocks
  do (was leaking to stdout).
- Made the remote-rewrite idempotent. A re-run used to break the
  `cd && remote remove && remote add` chain because remove fails when
  origin is already the desired URL. The loop now uses
  `git -C "$dir" remote set-url` when origin exists and `remote add`
  when it does not.
- Pre-created `~/sync`, `~/pictures`, `~/code`, `~/projects` so the
  clones don't fail on missing parent dirs.
- Wrapped each `git clone` in a `clone_if_missing` helper so a re-run
  skips destinations that already exist instead of erroring out.

README.md picks up the gitrepos.sh removal in the forking note.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 4a25f89..80f80cb 100644
--- a/README.md
+++ b/README.md
@@ -103,7 +103,7 @@ Every field has a default. Set only what you want to change. The config covers:
 - `DESKTOP_ENV`: `dwm`, `hyprland`, or `none`
 - `DWM_REPO`, `DMENU_REPO`, `ST_REPO`, `SLOCK_REPO`, `DOTEMACS_REPO`, `ARCHSETUP_REPO`: Git URLs for the suckless tools, the Emacs config, and this repo
 
-> **Forking note:** The upstream defaults point at the original author's personal Git server and assume a particular username. If you're adapting this for yourself, override the `*_REPO` variables in `archsetup.conf` to point at your own forks. Also review `scripts/post-install.sh` and `scripts/gitrepos.sh` — they clone personal repositories you won't want. The `archsetup` header, `init`'s temporary root password, and a handful of dotfiles (`.gitconfig`, `.ssh/config`, etc.) also carry author-specific values.
+> **Forking note:** The upstream defaults point at the original author's personal Git server and assume a particular username. If you're adapting this for yourself, override the `*_REPO` variables in `archsetup.conf` to point at your own forks. Also review `scripts/post-install.sh` — it clones personal repositories you won't want. The `archsetup` header, `init`'s temporary root password, and a handful of dotfiles (`.gitconfig`, `.ssh/config`, etc.) also carry author-specific values.
 
 ## Dotfile Management