shell: fish functions -> ~/.local/bin executables + bash/zsh ports; manage ~/.agents

- 16 cross-shell utilities converted to sh/bash chezmoi executables:
  ai c2p cp-appid extract_agents fab gdc gh-sonr-org-migrate ghg-clone
  ghn gho git-summary launch_omp_livediff_overlay lc-elir mdcp mdp pj
  (ghg-clone not named ghg: unrelated cargo binary owns that name)
- cwd/history helpers stay per-shell: yy c cd clip-last + ghg/ghn/gho
  cd-wrappers in bash/functions/ and zsh/functions/, loaded by rc files
- fish keeps only shell-state functions; converted ones now hit PATH
- cp-appid ignore gating moved to .local/bin path
- dot_agents/skills: 82 skills materialized from dotstate storage so
  dot_claude skill symlinks resolve on fresh bootstrap; dotstate
  profile/symlinks.json released .agents/skills .bashrc .zshrc

dot_local/bin/executable_launch_omp_livediff_overlay

@@ -0,0 +1,16 @@
+#!/bin/sh
+# Overlay omp on the current kitty window with a livediff split beside it.
+#
+# kitty appends -PID to config-file listen_on sockets, so a hardcoded
+# --to unix:@kitty-local never matches. kitty @ resolves the real
+# address from $KITTY_LISTEN_ON on its own.
+if [ -z "${KITTY_LISTEN_ON:-}" ]; then
+    echo "launch_omp_livediff_overlay: no kitty remote-control socket (KITTY_LISTEN_ON unset)" >&2
+    exit 1
+fi
+
+# omp overlays the current window; capture its window id
+wid=$(kitty @ launch --type=overlay-main --cwd=current omp) || exit
+
+# livediff side by side in the same tab; keep focus on omp
+exec kitty @ launch --match "id:$wid" --location=vsplit --keep-focus --cwd=current livediff