docs: import MCP Rust and Swift SDK tutorial packs

[johnxie]

Summary

Adds pack-bp with two official MCP SDK tracks:

• tutorials/mcp-rust-sdk-tutorial/ (8 chapters + index)
  • Covers rmcp crate setup, macro/router model, transport strategy, tasks, OAuth, release discipline, and production ops.
• tutorials/mcp-swift-sdk-tutorial/ (8 chapters + index)
  • Covers Swift client/server setup, transport/capability strategy, sampling and human-in-the-loop controls, lifecycle/shutdown, strict mode and batching, and upgrade guidance.

Also updates core discovery surfaces:

• README MCP path/catalog/stats updates
• categories/ai-ml-platforms.md MCP path + featured updates
• IMPORT_ROADMAP_TODO.md (pack-bo marked done; pack-bp added in progress)
• Regenerated tutorial/discoverability/status artifacts

Validation

• python3 scripts/docs_health.py --root . --baseline-file .github/baselines/broken-local-links.txt
• python3 scripts/check_index_format_v2.py --root .
• generator drift checks:
  • scripts/generate_tutorial_manifest.py
  • scripts/generate_discoverability_assets.py
  • scripts/update_tutorials_readme_snapshot.py
  • scripts/update_repo_status_docs.py
• outbound URL check for new index references

All checks passed.