Add privacy-safe feedback case export

[LE0-Lin]

Summary

• add �gent-config-score feedback to generate a local, privacy-minimized case draft
• exclude repository names, paths, instruction text, finding messages, and suppression reasons
• connect the draft to the structured real-world case form without uploading anything
• fix the community guide's stale pytest command

Verification

• full unit suite: 128 passed
• CLI demo and repository self-scan completed
• privacy regression verifies private project names and instruction contents are absent