v1.50.50 – v1.50.51 — 2026-06-19

• docs(admin): update admin handbook to v1.50.50 — security overview, system alerts, retroscan exclusions, training search, mailbox licensing, metered domains, also_sandbox
• docs(roadmap): mark metered billing, license enforcement, license dashboard as done
• feat(mailfilters): also_sandbox flag — atomically create sandbox_whitelist entry on sender-filter create (1.50.50)
• fix(installer): prerm/postrm missing stop+disable for freshclam/freshyara/mailname-sync units (1.50.51)