feat: add hive MCP registry repo

[VasuBansal7576]

Summary

• add the standalone hive-mcp-registry/ repo scaffold
• include the draft-07 manifest schema, validator, index builder, examples, template, CI, and docs
• verify the template and examples locally with the provided validation commands

Validation

• uv run --with jsonschema --with requests python scripts/validate.py registry/_template/manifest.json
• uv run --with jsonschema --with requests python scripts/validate.py registry/_examples
• uv run --with jsonschema --with requests python scripts/validate.py registry
• uv run python scripts/build_index.py

[github-actions]

PR Closed - Requirements Not Met

This PR has been automatically closed because it doesn't meet the requirements.

Missing: No linked issue found.

To fix:

1. Create or find an existing issue for this work
2. Assign yourself to the issue
3. Re-open this PR and add Fixes #123 in the description

Exception: To bypass this requirement, you can:

• Add the micro-fix label or include micro-fix in your PR title for trivial fixes
• Add the documentation label or include doc/docs in your PR title for documentation changes

Micro-fix requirements (must meet ALL):

Qualifies	Disqualifies
< 20 lines changed	Any functional bug fix
Typos & Documentation & Linting	Refactoring for "clean code"
No logic/API/DB changes	New features (even tiny ones)

Why is this required? See aden-hive#472 for details.