feat: look up local row ids by sync id for the sync plugin (Plugin-Sync#4)

packages/plugin-sdk/CHANGELOG.md

@@ -10,6 +10,7 @@ Plugin API 1.13.0.
 - `termix-plugin build` bundles `src/mobile` into the `contributes.mobile.entry` file, and `validate` checks that it exists
 - `@termix-ssh/plugin-sdk/frame-host` runs one plugin view outside the shell, with core's bridge, registries and CSS, so the mobile app can show `webview` plugins
 - SSH transport providers get the host's owner, sync id, connection origin and local only flag in `claims` and `open`, and core's SSH relay takes a `syncId` instead of a host id
+- `ctx.sync.host.entities.idsOf` maps sync ids to the local ids of the user's own rows of one type
 
 ### Fixed
 

packages/plugin-sdk/src/backend.ts

@@ -470,6 +470,12 @@ export interface PluginSyncHost {
     ensureCore: () => Promise<void>;
     onChanged: (listener: () => void) => () => void;
     onLocalWrite: (listener: () => void) => () => void;
+    /** Local ids of the user's own rows of a type, by sync id. Termix 26.10.6+. */
+    idsOf?: (
+      type: string,
+      userId: string,
+      syncIds: string[],
+    ) => Promise<Record<string, number>>;
   };
 
   /** Rows and bookkeeping of one local user's replica. */