refactor(config): default icons to ascii (#55)

* refactor(config): default icons to ascii

Problem: default icons used unicode characters (○, ✓, ●, ▸, ·, ↺)
which render poorly in some terminals and font configurations.

Solution: replace defaults with ascii equivalents (-, x, !, >, ., ~).
Users can still override to unicode or nerd font icons via config.

* ci: ignore library type checking

lua/pending/config.lua

@@ -82,12 +82,12 @@ local defaults = {
   },
   sync = {},
   icons = {
-    pending = '○',
-    done = '✓',
-    priority = '●',
-    header = '▸',
-    due = '·',
-    recur = '↺',
+    pending = '-',
+    done = 'x',
+    priority = '!',
+    header = '>',
+    due = '.',
+    recur = '~',
     category = '#',
   },
 }