Add GitHub plugin release imports and update discovery

src/lib/server/db/schema.sql

@@ -84,6 +84,17 @@ CREATE TABLE IF NOT EXISTS script_versions (
 );
 CREATE INDEX IF NOT EXISTS idx_script_versions_script ON script_versions(script_id);
 
+-- Provenance belongs to the exact binary version, including when it is rolled back.
+CREATE TABLE IF NOT EXISTS plugin_imports (
+    version_id   INTEGER PRIMARY KEY REFERENCES script_versions(id) ON DELETE CASCADE,
+    repository   TEXT NOT NULL,
+    release_id   INTEGER NOT NULL,
+    release_url  TEXT NOT NULL,
+    asset_id     INTEGER NOT NULL,
+    asset_name   TEXT NOT NULL,
+    published_at TEXT NOT NULL
+);
+
 CREATE TABLE IF NOT EXISTS server_scripts (
     server               TEXT NOT NULL REFERENCES servers(name) ON DELETE CASCADE,
     rel_path             TEXT NOT NULL,