Consolidate 16 migrations into one with UUID columns for all entity
IDs. TEXT is kept only for polymorphic fields (audit_logs.actor_id,
resource_id) and template names. The id package now generates UUIDs
via google/uuid, with Format*/Parse* helpers for the prefixed wire
format (sb-{uuid}, usr-{uuid}, etc.). Auth context, services, and
handlers pass pgtype.UUID internally; conversion to/from prefixed
strings happens at API and RPC boundaries. Adds PlatformTeamID
(all-zeros UUID) for shared resources.
Add SandboxProxyWrapper that intercepts requests with Host headers
matching {port}-{sandbox_id}.{domain} and proxies them through the
owning host agent's /proxy endpoint.
Authentication is via X-API-Key only (no JWT). The API key's team must
own the sandbox. Export EnsureScheme from lifecycle package for reuse.
Request flow: SDK -> Caddy -> CP catch-all -> Host Agent -> sandbox VM.
This is an intermediate state — needs further work for the full code
interpreter feature.
