Add MCP server packages: annas, bitwarden, email, namecheap, navidrome, ovhcloud, slskd

Packages MCP servers currently used by Hermes that were not yet in this
repo. Real hashes computed via nix build on wilkes; nix flake check passes.

- annas-mcp: Go, buildGoModule (re-added, previously dropped as broken)
- bitwarden-mcp: npm @bitwarden/mcp-server
- mcp-email-server: Python, buildPythonApplication
- namecheap-mcp: npm namecheap-api-mcp
- navidrome-mcp: npm navidrome-mcp
- ovhcloud-mcp: npm from GitHub, tsc build step
- slskd-mcp: Python, fastmcp wrapper

packages/slskd-mcp/package.nix

@@ -0,0 +1,49 @@
+{
+  lib,
+  stdenv,
+  fetchFromGitHub,
+  makeWrapper,
+  python3,
+}:
+
+let
+  python = python3.withPackages (
+    ps: with ps; [
+      fastmcp
+      httpx
+    ]
+  );
+in
+stdenv.mkDerivation rec {
+  pname = "slskd-mcp";
+  version = "0.1.0-unstable-2026-07-28";
+
+  src = fetchFromGitHub {
+    owner = "abl030";
+    repo = "slskd-mcp";
+    rev = "08e4373f41fddcceff8ea3240323e0c6258a373e";
+    hash = "sha256-ELUoAOOWmNoxoTjPxxAY00exN56lngSPs4wtn/GadQU=";
+  };
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  # generated/server.py is tracked in git; no build step needed.
+  dontBuild = true;
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/lib/slskd-mcp $out/bin
+    cp -r $src/generated $out/lib/slskd-mcp/
+    makeWrapper ${python}/bin/fastmcp $out/bin/slskd-mcp \
+      --add-flags "run $out/lib/slskd-mcp/generated/server.py"
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "MCP server for slskd (Soulseek daemon) - search, download, browse peers, private messages";
+    homepage = "https://github.com/abl030/slskd-mcp";
+    license = licenses.mit;
+    mainProgram = "slskd-mcp";
+    platforms = platforms.all;
+  };
+}