Add GitHub plugin release imports and update discovery

src/lib/plugin-github.ts

@@ -0,0 +1,38 @@
+export interface GithubPluginAsset {
+    id: number;
+    name: string;
+    size: number;
+    digest: string | null;
+}
+
+export interface GithubPluginRelease {
+    repository: string;
+    id: number;
+    tag: string;
+    url: string;
+    name: string;
+    notes: string;
+    publishedAt: string;
+    prerelease: boolean;
+    assets: GithubPluginAsset[];
+}
+
+export interface PluginSource {
+    version_id: number;
+    repository: string;
+    release_id: number;
+    release_url: string;
+    asset_id: number;
+    asset_name: string;
+    published_at: string;
+}
+
+export interface PluginUpdate {
+    pluginId: number;
+    name: string;
+    source: PluginSource | null;
+    release: GithubPluginRelease | null;
+    status: 'untracked' | 'available' | 'imported' | 'current' | 'ahead' | 'error';
+    versionId?: number;
+    error?: string;
+}