revert(shell): move iris integration to the iris branch

Reverts 43dfe48, 0692ae3, e0cdcd6 and the cable-description half of
098da70 (the star-prompt stats stay). master returns to the pre-iris
shell setup: atuin in fish/zsh/bash, the down -> pj binding with
PJ_QUIET, and the fish/zsh key bindings as they were. The iris work
lives on the `iris` branch.

dot_config/zsh/functions/czs.zsh

@@ -1,35 +0,0 @@
-# czs: chezmoi re-add drifted files, then commit + push the source repo.
-# Port of functions/czs.fish. Optional targets scope the status view and the
-# re-add (e.g. `czs ~/.config/fish`); no args = all managed files.
-czs() {
-    local drift src ahead
-    drift=$(chezmoi status "$@") || return
-
-    if [[ -n $drift ]]; then
-        print -r -- $drift
-        # re-add takes the local (destination) contents as truth for modified
-        # files; templates are never overwritten, non-file entries are ignored.
-        chezmoi re-add "$@" || return
-    else
-        echo "chs: in sync — nothing to re-add"
-    fi
-
-    # Commit + sync the source repo (~/.local/share/chezmoi).
-    src=$(chezmoi source-path)
-    if [[ -n $(git -C $src status --porcelain) ]]; then
-        git -C $src add -A &&
-            git -C $src commit --quiet -m 'chs: re-add drifted files' || return
-        echo "chs: committed $(git -C $src rev-parse --short HEAD)"
-    fi
-
-    # Push anything unpushed: this commit and leftovers from a failed push.
-    # --autostash tolerates post-commit hooks re-dirtying the tree mid-sync.
-    ahead=$(git -C $src rev-list --count @{upstream}..HEAD 2>/dev/null || echo 0)
-    if (( ahead > 0 )); then
-        git -C $src pull --rebase --autostash --quiet &&
-            git -C $src push --quiet &&
-            echo "chs: pushed $ahead commit(s) to $(git -C $src remote get-url origin)"
-    else
-        echo "chs: remote up to date"
-    fi
-}

dot_config/zsh/functions/y.zsh

@@ -1,2 +0,0 @@
-# y: same as yy (fish has both names) — yazi, then cd to its exit directory.
-y() { yy "$@"; }