fix: Remove servers with invalid package entries (#434)

Fixes #49

This PR removes 36 servers from the seed file that had package entries
pointing to non-existent packages on PyPI or npm registries.

## Summary

The issue reported that many servers in the registry had `packages`
fields referencing non-existent packages. These servers either never
published to package registries or used incorrect identifiers.

## Changes
- **Removed 36 servers** that had invalid package references
- Created validation tools to identify and fix these issues

## Affected Servers
Servers removed include those pointing to non-existent:
- PyPI packages: mcp-aiven, inkeep-mcp-server, needle-mcp, and others
- npm packages: redis-mcp-server, mcp-server-applescript, ppl-ai, and
others

The registry now contains only servers with valid, installable packages.

Author: domdomegg