[callumalpass]

Integrates round 2 of the overnight campaign. Every fix comes with a regression test that failed first.

One merge conflict was resolved: SyncHistoryStore.acknowledge (from ux) is rewritten in the serialized, torn-tail-safe style from reliability.

• Normalize malformed stored sync policies without discarding enrollment identity
• Dismiss pinned sync notices without erasing their history
• Prove merged-resolution retries survive checkpoint failure without copies
• Vary offline convergence seeds and inject quota errors during settlement
• Exercise seeded insert/delete mutations and exact kept-both YAML round trips
• Inspect local projection changes immediately when sync settings change
• Keep consent reasons ahead of roomy actions and an honest review heading
• Trim identical bulk so small edits in large notes merge without copies
• Use conditional Vault.process for invalid UTF-8 receive-only repairs
• Keep long sync paths and recovery actions usable in narrow panes
• Keep both when the same new field was placed at incompatible positions
• Contain rejected host operations inside the scheduler retry boundary
• Persist merged text before clearing its conflict so restarts cannot lose hosted edits
• Only reserve a text-write echo after the conditional check succeeds
• Consume each write echo once so immediate user edits still trigger sync
• Keep conflict-copy evidence visible and history disclosures stable
• Exercise offline edit convergence and checkpoint quota-failure recovery
• Retain the conflict when both merge and recovery-copy writes fail
• Keep full record and type-impact scans out of Sync and Issues
• Name the destination of deletions and renames in sync reviews
• Start the first download after connecting without a redundant review
• Keep failed or unresolved conflict settlements out of up-to-date results
• Serialize complete conflict settlements with sync and inspection
• Preserve sync control focus even for quoted file paths
• Ignore inspections and status responses from retired mirror enrollments
• Prove rejected, binary, rename and occupied-path conflicts settle losslessly
• Serialize desktop HTTP headers in their owning process so multipart uploads retain ETags
• Make workspace tabs keyboard navigable without losing focus
• Keep chasing pending work after the bounded sync round limit
• Yield cached record scans so large collections do not block typing
• Serialize history snapshots and repair torn tails before append
• Report settings success only after the sync scope is saved
• Build history ledgers only when their disclosures are open
• Port SDK conflict-resolution fencing to prevent snapshot-wait edit loss
• Keep approval reachable and cancellable when restoring sync
• Refuse queued text writes through a renamed or replaced TFile
• Allow storage to reopen after a transient IndexedDB failure

Validation: npm test (332 pass, plus 10 lossless round trips), npm run lint, and npm run check:mobile.