Show Plex security advisory status after validation

[bullmoose20]

After Plex validation, show whether the connected server addresses PLEX-PMS-2026-09 using the version on the freshly validated Plex object. Affected versions show a red update warning with the installed version, 1.43.3.10861 minimum and official Plex link; patched versions show a small advisory-specific status, and unavailable versions remain unknown. Saving configuration remains available.

• Explicit validation refreshes the connection and invalidates its validation/metadata/library-discovery cache entries. Cached telemetry cannot override the new security assessment. Revisit the Plex page or select Validate again after an upgrade to refresh status.
• Clear status on connection edits, revalidation and unavailable responses; ignore late responses for older credentials or older requests. Preserve existing validation failure callback behavior for other wizard pages.
• Reuse the existing local log recommendation engine with the same canonical advisory evaluator as online Logscan. Group repeated observations per server/advisory, retain historical evidence, and count plex_security findings semantically. Keep the older vulnerability range without duplicate warnings and preserve the existing compatibility parser API.

Logscan owns the authoritative source. modules/_vendor/plex_security.py is identical to its committed source and pinned in the adjacent manifest. scripts/sync_plex_security.py synchronizes and checks a committed local Logscan checkout. The audit found separate application analyzers with no importable shared core; future advisory changes require syncing and releasing both repositories. No runtime dependency, backend service or advisory HTTP request is added. See docs/plex-security.md.

Companion authoritative source and portal integration: Kometa-Team/Logscan#83. Merge that source change first to establish its ownership; this Quickstart change has no runtime dependency on the portal deployment.

Validation:

• Plex/analyzer/validation/authentication regression suite passed; final advisory, fresh/stale telemetry and legacy-version regressions: 41 passed.
• Targeted JavaScript suite: 108 passed, including connection edits, revisit refresh, unavailable responses, revalidation and response ordering.
• Source parity/checksum, Ruff, Black, ESLint, shared-core mypy and commit hooks passed.
• The standalone local spelling wrapper skipped because Aspell is unavailable; the commit spelling hook passed.
• No production deployment or merge performed.

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