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_config/bash/functions/cd.bash

@@ -0,0 +1,23 @@
+# cd with zoxide fallback, else builtin cd.
+cd() {
+    local rc target
+    if [ $# -eq 0 ]; then
+        builtin cd "$HOME"
+    elif [ "$1" = - ]; then
+        builtin cd -
+    elif builtin cd "$1" 2>/dev/null; then
+        : # exact path resolved, nothing else to do
+    elif command -v zoxide >/dev/null 2>&1; then
+        target=$(zoxide query -- "$1" 2>/dev/null)
+        if [ -n "$target" ]; then
+            builtin cd "$target"
+        else
+            builtin cd "$1" # let builtin cd surface the real error
+        fi
+    else
+        builtin cd "$1"
+    fi
+    rc=$?
+    command -v zoxide >/dev/null 2>&1 && zoxide add "$PWD" 2>/dev/null
+    return $rc
+}