Merge pull request #2016 from ludovic111/feat/mod-ui-key

🤖 Agent: Players rebind a mod's keys on its Options > Mods page (the game's own key rows, saved in horizon-mods.txt), with no WIT type change, so the published mods keep loading. Verified with main merged: clippy, the client, mods and SDK tests, and the in-game check in both modes (24/24).

docs/api/mods-reference.md

@@ -278,7 +278,7 @@ A mapping as the player has bound it.
 | Function | Signature | What it does |
 | --- | --- | --- |
 | `claim-items` | `func(ids: list<string>)` | The items whose use the mod handles instead of the game, by id (at most 64). Replaces the previous list. |
-| `register-key` | `func(name: string, label: string, key: string) -> result<_, string>` | A key of the mod's: `name` comes back in `key-down` and `key-up`, `label` says what it does, `key` is the key as options.txt writes it (`key.keyboard.r`). At most 16; an unknown key is an error. |
+| `register-key` | `func(name: string, label: string, key: string) -> result<_, string>` | A key of the mod's: `name` comes back in `key-down` and `key-up`, `label` says what it does, `key` is the key as options.txt writes it (`key.keyboard.r`), the default: the player can bind another one on the mod's page in Options > Mods, and that one wins. At most 16; an unknown key is an error. |
 | `held` | `func() -> option<held-item>` | The main hand's stack, as of this tick; none when it is empty. |
 | `poll` | `func() -> list<event>` | The events since the last call, oldest first. |
 | `claim-wheel` | `func(on: bool)` | Takes the mouse wheel while playing (true) or gives it back: while taken, its steps are the mod's `wheel` events and the hotbar doesn't move. The game gives it back when the mod stops. |

docs/api/stability.md

@@ -26,12 +26,13 @@ promise, how something is deprecated and removed, and the tests that keep old mo
 ## What counts as a breaking change
 
 Breaking: removing or renaming anything; changing a type, a default, a unit or a meaning; making something optional
-required; refusing input that was accepted; a new case in a WIT `enum` or `variant` the game sends to mods (an older
-component cannot decode it); a JSON field that changes type.
+required; refusing input that was accepted; any change to a WIT type a function uses, a new `enum` or `variant` case
+included, in either direction (the runtime links a component only when each imported function's types match exactly:
+a mod built before the change no longer loads); a JSON field that changes type.
 
 Not breaking: a new function, interface, capability, command, endpoint, tool or `server.toml` key; a new optional
-argument or JSON field (readers must ignore fields they don't know); a new WIT case the mod *sends* (the game decodes
-every case it ever served); faster, or fixing behaviour to what the reference already says.
+argument or JSON field (readers must ignore fields they don't know); a new WIT function or type (mods built earlier
+don't import it); faster, or fixing behaviour to what the reference already says.
 
 ## Stability levels