chore: add knip and remove the dead code it reports (#247)

Adds knip (pnpm knip, knip.ts covering src, scripts, perf and e2e) and runs it in the CI frontend job. Removes what it reported: the unused codemirror and @types/dompurify dependencies, exports and test hooks used nowhere (AppLogo, Tooltip, barrel re-exports, duplicate default exports of lazily loaded settings pages), the unused iterateAll helper, and the zh entry for a deleted notification. rustfmt (used by lint-staged) is ignored as a toolchain binary.

Co-authored-by: jaw52 <[email protected]>

package.json

@@ -15,6 +15,7 @@
     "lint": "oxlint",
     "format": "oxfmt",
     "format:check": "oxfmt --check",
+    "knip": "knip",
     "typecheck": "tsrs --noEmit && tsrs -p tsconfig.node.json --noEmit && tsrs -p perf --noEmit && tsrs -p scripts --noEmit",
     "gen:bindings": "cargo test -p openidea --test export_bindings",
     "gen:theme-docs": "node scripts/theme/gen-docs.ts",
@@ -57,7 +58,6 @@
     "@xterm/xterm": "^6.0.0",
     "anser": "^2.3.5",
     "clsx": "^2.1.1",
-    "codemirror": "^6.0.2",
     "dompurify": "^3.4.17",
     "emmet": "2.4.11",
     "immer": "^11.1.21",
@@ -74,12 +74,12 @@
     "@testing-library/jest-dom": "^7.0.1",
     "@testing-library/react": "^16.3.3",
     "@testing-library/user-event": "^14.6.8",
-    "@types/dompurify": "^3.2.0",
     "@types/node": "^26.6.5",
     "@types/react": "^19.1.8",
     "@types/react-dom": "^19.1.6",
     "@vitejs/plugin-react": "^6.0.2",
     "jsdom": "^30.1.3",
+    "knip": "^6.43.0",
     "lint-staged": "^17.6.0",
     "oxfmt": "^0.74.0",
     "oxlint": "^1.89.0",