Make protect_charms_from_sell actually configurable

It already read Config().char.get("protect_charms_from_sell", True) in
personal.py's drop/sell guard, but the key was never added to the char
config dict builder in config.py, so setting it in an ini file did
nothing — charms were unconditionally undroppable regardless of the
pickit verdict. Wired it up the same way protect_shields_from_sell
already works. Defaults to 1 (protected, unchanged behavior) so this
is opt-in only.

config/params.ini

@@ -371,6 +371,10 @@ runs_per_stash=4
 sell_junk=1
 ; protect_shields_from_sell: 1 = never vendor items with "shield" in detected name (recommended safety)
 protect_shields_from_sell=1
+; protect_charms_from_sell: 1 = never drop/vendor charms regardless of pickit verdict
+; (recommended safety — a misread charm can't be un-dropped). Set to 0 to let your
+; pickit rules decide keep/discard for charms same as any other item.
+protect_charms_from_sell=1
 ; pick_rares_for_gold: 1 = pick all yellow (rare) ground items; non-keep rares will be sold
 ; Requires sell_junk=1 to convert extra pickups into gold.
 pick_rares_for_gold=0

src/config.py

@@ -376,6 +376,7 @@ class Config:
             "gamble_items": False if not self._select_val("char", "gamble_items") else self._select_val("char", "gamble_items").replace(" ","").split(","),
             "sell_junk": bool(int(self._select_val("char", "sell_junk"))),
             "protect_shields_from_sell": bool(int(self._select_optional("char", "protect_shields_from_sell", "1"))),
+            "protect_charms_from_sell": bool(int(self._select_optional("char", "protect_charms_from_sell", "1"))),
             "pick_rares_for_gold": bool(int(self._select_optional("char", "pick_rares_for_gold", "0"))),
             "pick_gold": bool(int(self._select_optional("char", "pick_gold", "1"))),
             "enable_no_pickup": bool(int(self._select_val("char", "enable_no_pickup"))),