NixOS Discord withVencord breaks after Discord's rspack update (i.A is not a constructor): pin Vencord >= 1.15.16

Symptom: Discord (pkgs.discord.override {withVencord = true;}) stops loading after Discord pushed a new web bundle (Nov 2026). ~/.config/discord/logs/renderer_js.log shows Vencord WebpackPatcher then Uncaught TypeError: i.A is not a constructor, and logging stops there each launch. Cause: Discord moved its client to rspack; Vencord fixed it in v1.15.16 ("Fix all plugins for new rspack update"). nixpkgs (even nixos-unstable at 1.15.13) lagged. Fix: discord.override { withVencord = true; vencord = pkgs.vencord.overrideAttrs (finalAttrs: old: { version = "1.15.16"; src = old.src.override { tag = "v${finalAttrs.version}"; hash = "sha256-aUJubLJpyLAZWiOezqFxPY6oVPgWVPQpajFqrJvrO9U="; }; patches = []; postPatch = ""; pnpmDeps = old.pnpmDeps.overrideAttrs { inherit (finalAttrs) src patches postPatch; outputHash = "sha256-HS8uZNepvDefjrsG3buVLFCVv7sHvazcwdpcT3EQ/78="; }; }); }. Gotcha: nixpkgs fix-deps.patch (bumps @types/react 18.3.1 -> 19.1.0 in pnpm-lock) FAILS to apply on 1.15.16 since upstream already uses React 19 types via catalog; drop both patches and postPatch, and pass them into pnpmDeps too or its hash is computed against the old patch. pnpmDeps hash depends on pnpm fetcherVersion 4 in that nixpkgs.