chore(release): v0.10.1

CHANGELOG.md

@@ -7,6 +7,31 @@ change type. Preview the next one with `ludic dev release --dry-run`.
 A released section may carry a hand-written summary paragraph above its groups
 (v0.2.0 has one); the generated bullets below it are not edited by hand.
 
+## v0.10.1 — 2026-09-11
+
+### Fixes
+
+- **`Os.save_dir` / `Os.config_dir` / `Os.cache_dir` follow the platform.** They were the
+  macOS layout everywhere, so a game built on Linux wrote its saves to
+  `~/Library/Application Support` — a directory that means nothing there. Naming the
+  right directory is the entire reason a program calls these instead of building a path.
+
+  | | macOS | Linux |
+  | --- | --- | --- |
+  | `save_dir` | `~/Library/Application Support/<app>` | `$XDG_DATA_HOME` or `~/.local/share/<app>` |
+  | `config_dir` | `~/Library/Application Support/<app>` | `$XDG_CONFIG_HOME` or `~/.config/<app>` |
+  | `cache_dir` | `~/Library/Caches/<app>` | `$XDG_CACHE_HOME` or `~/.cache/<app>` |
+
+  An XDG variable that is set but empty falls back to the default, as the spec requires.
+  macOS is unchanged to the byte — `save_dir` and `config_dir` stay the same directory
+  there, because Apple's home for a config file that is not an `NSUserDefaults` plist is
+  Application Support too, and a shipped game's settings must not move out from under it.
+  On Linux XDG separates the two and so does this.
+
+  One consequence worth stating plainly: a game already shipped on Linux was writing to
+  the old macOS-shaped path, and this moves it. Those files are not migrated for you —
+  they are wherever `~/Library/Application Support/<app>` ended up on that machine, and a
+  game that has Linux players should move them once on startup.
 ## v0.10.0 — 2026-09-11
 
 ### Features