feat(config): add is_never_shown helper for mini.files filter

lua/config/ignore_patterns.lua

@@ -1,7 +1,7 @@
 --- Shared ignore patterns for file explorers and pickers
 --- This module provides a centralized list of patterns to ignore across
---- snacks.picker and other file browsing tools. (The never_show lists were
---- consumed by neo-tree, now replaced by mini.files; kept as reference data.)
+--- snacks.picker and other file browsing tools. (The never_show lists are
+--- consumed by the mini.files explorer filter, see `is_never_shown`.)
 ---
 --- Everything here is fast-event-context safe (pure Lua + libuv only):
 --- snacks picker transforms run inside async/uv callbacks where vimL
@@ -276,6 +276,28 @@ function M.get_all_patterns(dir)
   return vim.list_extend(vim.list_extend({}, M.patterns), M.read_rgignore(dir))
 end
 
+--- Check a single file/directory name against the never_show lists
+--- (exact names + glob patterns). Used by the mini.files content filter.
+--- Pure Lua; lists are compiled lazily on first call.
+--- @param name string entry basename (not a path)
+--- @return boolean
+local never_show_set ---@type table<string, true>?
+local never_show_compiled ---@type string[]?
+function M.is_never_shown(name)
+  if never_show_set == nil then
+    never_show_set = {}
+    for _, n in ipairs(M.never_show) do
+      never_show_set[n] = true
+    end
+    never_show_compiled = compile_globs(M.never_show_patterns)
+  end
+  if never_show_set[name] then return true end
+  for _, pat in ipairs(never_show_compiled) do
+    if name:match(pat) then return true end
+  end
+  return false
+end
+
 --- Create a filter for snacks picker `transform` options.
 --- Snacks contract: return `false` to DROP an item, `true`/`nil` to keep it
 --- (returning nil keeps the item!). Runs per item in a fast event context,