v1.6.0-rc.2

Full Changelog: v1.6.0-rc.1...v1.6.0-rc.2

[1.6.0-rc.2] — 2026-07-18

"Version update" container filter (#538). The Containers filter bar gains a Version Update kind option that shows only real semver upgrades (major, minor, patch) and hides digest-only churn — the noise that dominates the dashboard on fleets that rebuild images daily in CI. Like every other container filter, it round-trips through the URL (?filterKind=version), so the filtered view can be saved as a bookmark for one-click access.

Repair rebuilds no longer reset the registry-reconciled digest (#541). When the fast refresh path repairs a stored container's broken image reference, the reconciled digest.value — the security scan-group key — is now preserved unless the repo digest genuinely changed (image re-pulled), the same stickiness rule the slow-path rebuild gained for #536.
Containers with a stored watch error refresh on the fast path (#542). An error from the previous cycle no longer routes a known container through the full first-discovery enumeration — image/label/tag re-resolution plus an O(n) stale-entry scan of the store — on every cron. Errored-but-known containers reuse the same cheap refresh as healthy ones, and broken image references still self-heal via the unconditional repair check.
Last-known-good update state survives watch errors (#543). A failed watch cycle — registry timeout, rate limit, transient network error — no longer erases the previous successful comparison. The stored result, updateAvailable, updateKind, and current release notes are preserved alongside the recorded error until a later cycle succeeds, so the UI keeps showing the last known update state with the error annotated next to it instead of a blank.
Portwing WS Welcome frames now report the actual server version — the endpoint had hard-coded 1.5.0 since v1.5.0, so v1.5.1/v1.5.2/v1.6.0-rc.1 servers all identified as 1.5.0 to agents (#550 review finding)