chore: sync community files

[albert20260301]

Summary

• add the managed GitHub funding metadata
• add shared bug report and feature request issue forms
• add the shared pull request template

Impact

• Repository metadata and contributor workflow only.
• No SDK source, package metadata, runtime behavior, or release automation changed.

Validation

• git diff --check
• python3 YAML parse for .github/FUNDING.yml and issue forms

[albert20260301]

@leo-altertable could you review this?

I picked you because the touched files are contributor-facing metadata with no non-Albert blame signal, and your Python SDK ownership is the strongest stack match. CI is pending; the main review focus is whether these shared templates fit the Lakehouse Python repo's contributor workflow.