- www host: /_* and /api/* proxy to pocketbase :8090, everything else to
the TanStack app; redir /_ /_/ for the admin path
- cms host unchanged: redir / -> /_/
- migration: legacy per-host marker blocks are removed before the new
combined block is installed
- cms.ts: PB file urls are now same-origin relative (/api/files/...) —
browsers could never load the old 127.0.0.1:8090 urls; validated the
rendered Caddyfile with caddy:2