Repair pasteback confirmation and Paste Again feedback

[r3dbars]

Summary

Fresh-main replacement for PR #1552 covering pasteback confirmation truth, Paste Again ownership, focus-target adapters, and clipboard recovery.

• AX-confirmed delivery is distinct from provider-ambiguous and genuinely unconfirmed delivery.
• Deterministic Codex, Notes, and browser target adapters exercise the production paster path without fake confirmation injection.
• Paste Again is one-shot, paste-only, and cannot auto-send or re-arm retry ownership.
• Focus changes, timeout/cancellation, retry ownership, and clipboard restoration are covered.
• Telemetry remains coarse and privacy-safe.

Exact proof

• Base: 8d613b87da0373c04dd1f64c52adbf4109425ce9
• Head: 8d045c24486e14ef0d56c921267af8788cf62279
• git diff origin/main...HEAD --check
• python3 scripts/dev/check-build-source-lists.py
• shell syntax checks
• bash build-deps.sh --force
• bash build.sh --no-open
• bash run-tests.sh: 13,255 passed, 0 failed
• bash run-tests.sh --filter ClipboardRestoringTextPasterTests: 157 passed, 0 failed
• bash run-slow-pasteback-smoke.sh: 9/9 passed
• exact-head Codex review against origin/main: clean, no actionable findings

Integration smoke was not required by the path matrix because this change does not touch Meeting, TranscriptedCore, or Package.swift.

Proof boundary

Manual GUI focus behavior, Paste Again feel, and live hardware proof remain UNKNOWN. No manual GUI proof is claimed. No transcript text, raw clipboard data, paths, or app identity is sent in telemetry.

The exact-head review fixed the cancellation ownership gap in 2b4a7a97. The later discard behavior was reviewed and retained intentionally: dismissing Paste Again keeps fresh dictation text available for manual Cmd+V recovery; full cancellation restores the pre-dictation clipboard.

lanes used: Codex=implementation, build/tests, and exact-head review (/tmp/transcripted-pasteback-codex-review-final2.txt); Claude=independent adversarial review (/Users/redbars/.codex/maestro/runs/20260717T232747Z-pasteback-review-claude); Local=attempted but unavailable (/Users/redbars/.codex/maestro/runs/20260717T232925Z-pasteback-review-local-local); Windows=skipped.

[r3dbars]

Superseded duplicate pasteback lineage; current-main replacement #1564 is now merged.