feat(packages): ludic.settings - a settings store as data: typed reads and writes by id, clamping, rescue values, per-key persistence, a fact per change

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.settings/rules.ludic

@@ -0,0 +1,35 @@
+# ludic.settings/rules.ludic - the whole store at once: every setting to its default, every one
+# held to its range, and the rescue set. None of these is news: whoever calls them applies it all
+export function settings_reset_all() -> void {
+  sg_init()
+  for i in 0 .. len(sg_defs) {
+    sg_num[i] = sg_defs[i].num
+    sg_text[i] = sg_defs[i].text
+  }
+}
+
+# a hand-edited file, or one from a build with more choices, never hands the game a value it has
+# no case for
+export function settings_clamp_all() -> void {
+  sg_init()
+  for i in 0 .. len(sg_defs) { sg_num[i] = settings_held(i, sg_num[i]) }
+}
+
+# the values every machine can run: each setting marked `rescue` back to its default, and the
+# rest (keys, language, volume) left the player's
+export function settings_rescue() -> void {
+  sg_init()
+  for i in 0 .. len(sg_defs) {
+    if sg_defs[i].rescue {
+      sg_num[i] = sg_defs[i].num
+      sg_text[i] = sg_defs[i].text
+    }
+  }
+}
+
+# whether a setting is on the rescue list at its safe value
+export function settings_is_safe(id: int) -> bool {
+  let d = sg_defs[id]
+  if not d.rescue { return true }
+  return sg_num[id] == d.num and sg_text[id] == d.text
+}