Add knip unused code & dependency analyser (#1441)

knip.ts

@@ -0,0 +1,16 @@
+import { KnipConfig } from "knip";
+
+export default {
+    entry: ["src/electron-main.ts", "src/preload.ts", "electron-builder.js", ".eslintrc-*.js", "scripts/**", "hak/**"],
+    project: ["**/*.{js,ts}"],
+    ignoreDependencies: [
+        // Brought in via hak scripts
+        "keytar",
+        "matrix-seshat",
+        // Needed by `electron-builder`
+        "electron-builder-squirrel-windows",
+        // Required for `action-validator`
+        "@action-validator/*",
+    ],
+    ignoreBinaries: ["jq", "scripts/in-docker.sh"],
+} satisfies KnipConfig;