Memo 079: Clean up stale memo-064-* branches

[a6b8]

Classification

Polish — git hygiene.

Background

Memo 079 Welle 1 inventory found 2 unmerged remote branches:

Branch	Tip commit	Status
`origin/memo-064-content-ui-audit`	05afd87 (refs #87, no PR)	Source branch of merged PR #88. Has additional commits after the merge that reference a non-existent #87.
`origin/memo-064-qa-fixes`	56af64a (refs #89, no PR)	4 commits ahead of main, no PR ever opened. Unmerged work.

Expected

Decide per branch:

• Delete `memo-064-content-ui-audit` if leftover commits are dead code (merged PR Memo 064: Webseite Content & UI Audit v2 #88 already on main).
• Open PR or delete `memo-064-qa-fixes` (review unmerged content first).

Risk if untouched

• Dead branches accumulate
• Confusion about which work landed

Scope

Triage T#20 (Welle 1 git-hygiene).

References

• Memo 079 REV-04 Triage T#20
• Welle 1 Inventory .memo/079-repo-hygiene-triage/rollout/welle-1-inventory.md