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/mcp-email-server/package.nix

@@ -0,0 +1,57 @@
+{
+  lib,
+  python3Packages,
+  fetchFromGitHub,
+}:
+
+python3Packages.buildPythonApplication rec {
+  pname = "mcp-email-server";
+  version = "1.4.1";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "Wh1isper";
+    repo = "mcp-email-server";
+    rev = "a1668a912db08373cc109b7482363129c75fd646";
+    hash = "sha256-Zt+198bQMthp6Mxmmsd7eTh9iybqOXWuVqLylzfUiIg=";
+  };
+
+  build-system = with python3Packages; [
+    hatchling
+  ];
+
+  dependencies = with python3Packages; [
+    aioimaplib
+    aiosmtplib
+    anyio
+    beautifulsoup4
+    click
+    jinja2
+    keyring
+    loguru
+    mcp
+    pydantic
+    pydantic-settings
+    starlette
+    tomli-w
+    typer
+    email-validator
+    filelock
+    uvicorn
+  ];
+
+  doCheck = false;
+  # mcp transitively requires filelock>=3.32.2 but nixpkgs ships 3.29.7;
+  # the runtime-deps check is too strict, so skip it (same as nextcloud-mcp-server).
+  dontCheckRuntimeDeps = true;
+
+  pythonImportsCheck = [ "mcp_email_server" ];
+
+  meta = with lib; {
+    description = "MCP server for email - send, receive, search, and manage mail over IMAP/SMTP";
+    homepage = "https://github.com/Wh1isper/mcp-email-server";
+    license = licenses.mit;
+    mainProgram = "mcp-email-server";
+    platforms = platforms.all;
+  };
+}