feat: optimize ag and apt snippet collections

AG (The Silver Searcher):
- Remove old snippets (5 removed)
- Add comprehensive search commands (38 added)
- Cover: search modes, output formats, file types, filters

APT (Debian/Ubuntu package manager):
- Remove old snippets (10 removed)
- Add comprehensive package commands (36 added)
- Cover: update/upgrade, install/remove, search, sources, dependencies

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Alfred.alfredpreferences/snippets/apt/apt cache policy [E3F4A5B6-2C7D-9E0F-1A2B-3C4D5E6F7A8B].json

@@ -0,0 +1,8 @@
+{
+  "alfredsnippet" : {
+    "snippet" : "apt-cache policy ",
+    "uid" : "E3F4A5B6-2C7D-9E0F-1A2B-3C4D5E6F7A8B",
+    "name" : "顯示套件詳細來源 (舊指令)",
+    "keyword" : ""
+  }
+}