ZSH: Add data-driven plugin system with ignore list, migrate autosuggestions

Plugins are defined in zsh_plugins.yaml and pulled as git-repo chezmoi
externals into ~/.config/zsh/plugins/. A plug:: namespace provides
load, is_loaded, and an ignore list (plugins_ignore) for temporarily
disabling plugins locally. All plug:: state is cleaned up after startup
via dot::defer.

Replaces the old single-file autosuggestions external with the new
plugin system. Autosuggestions now uses (history completion) strategy.

Author: jdevera

home/.chezmoidata/zsh_plugins.yaml

@@ -0,0 +1,9 @@
+# ZSH plugins: downloaded as chezmoi externals, loaded by load_plugin
+# Fields:
+#   repo:        GitHub owner/repo (required)
+#   description: what the plugin does
+#   name:        (optional) plugin directory name, defaults to repo name
+#   source:      (optional) file to source, defaults to <name>.plugin.zsh
+zsh_plugins:
+  - repo: zsh-users/zsh-autosuggestions
+    description: "Fish-like autosuggestions for zsh"

home/.chezmoiexternals/zsh_autosuggestions.toml

@@ -0,0 +1,6 @@
+{{- range .zsh_plugins -}}
+{{ $name := default (base .repo) (index . "name") }}
+[".config/zsh/plugins/{{ $name }}"]
+    type = "git-repo"
+    url = "https://github.com/{{ .repo }}.git"
+{{ end -}}

home/.chezmoiexternals/zsh_plugins.toml.tmpl

@@ -0,0 +1,2 @@
+# Plugins listed here (one per line) will not be loaded.
+# This file is not overwritten by chezmoi — local changes are preserved.

home/dot_config/zsh/create_plugins_ignore

@@ -0,0 +1,50 @@
+# Plugin loader with local ignore list support
+#
+# Reads ~/.config/zsh/plugins_ignore once into an associative array.
+# plug::load checks against it and sources the plugin if not ignored.
+# plug::is_loaded checks if a plugin was successfully loaded.
+
+typeset -A _plug_ignore=()
+typeset -A _plug_loaded=()
+typeset -i _plug_ignore_ready=0
+
+_plug_load_ignore_list() {
+    _plug_ignore_ready=1
+    local ignore_file=~/.config/zsh/plugins_ignore
+    [[ -f $ignore_file ]] || return
+    local line
+    while IFS= read -r line; do
+        # Skip comments and blank lines
+        [[ -z $line || $line == \#* ]] && continue
+        _plug_ignore[$line]=1
+    done < "$ignore_file"
+}
+
+plug::load() {
+    local name=$1
+    local source_file=${2:-${name}.plugin.zsh}
+    local plugin_dir=~/.config/zsh/plugins/$name
+
+    # Load ignore list on first call
+    if (( ! _plug_ignore_ready )); then
+        _plug_load_ignore_list
+    fi
+
+    # Skip ignored plugins
+    if (( ${+_plug_ignore[$name]} )); then
+        return
+    fi
+
+    local full_path=$plugin_dir/$source_file
+    if [[ -f $full_path ]]; then
+        source "$full_path"
+        _plug_loaded[$name]=1
+    fi
+}
+
+plug::is_loaded() {
+    (( ${+_plug_loaded[$1]} ))
+}
+
+dot::defer "unset _plug_ignore _plug_loaded _plug_ignore_ready"
+dot::defer "unfunction _plug_load_ignore_list plug::load plug::is_loaded"

home/dot_config/zsh/exact_private_zsh.d/private_005_plugin_loader.zsh

@@ -0,0 +1,8 @@
+# Load ZSH plugins
+# Generated from .chezmoidata/zsh_plugins.yaml
+
+{{ range .zsh_plugins -}}
+{{ $name := default (base .repo) (index . "name") -}}
+{{ $source := default (printf "%s.plugin.zsh" $name) (index . "source") -}}
+plug::load {{ $name }} {{ $source }}
+{{ end -}}

home/dot_config/zsh/exact_private_zsh.d/private_006_plugin_load.zsh.tmpl

@@ -0,0 +1,6 @@
+# Plugin configuration
+# Runs after plugins are loaded (006), uses plug::is_loaded for conditionals
+
+if plug::is_loaded zsh-autosuggestions; then
+    ZSH_AUTOSUGGEST_STRATEGY=(history completion)
+fi