feat: minimal self-host relay stack (CF + Clerk + Supabase, optional Axiom/APNs)

[gfsaaser24]

Summary

• prefer a generic external Postgres configuration for Supabase Hyperdrive while retaining the managed PlanetScale path as a compatibility fallback
• omit Axiom providers, datasets, tokens, Worker export, and client tracing output when the Axiom token/org pair is absent
• omit APNs queues and delivery runtime when the APNs credential set is incomplete, with agent activity delivery provided by a no-op service
• document the Cloudflare + Clerk + Supabase minimum stack, exact Supabase Session pooler mapping, schema initialization, and required versus optional GitHub settings

Validation

• vp run --filter t3code-relay typecheck
• 54 focused tests across deploy output, optional config, disabled APNs, and existing APNs delivery/queue behavior
• parsed .github/workflows/deploy-relay.yml with PyYAML
• targeted vp fmt --check
• git diff main...HEAD --check

Targeted vp lint was attempted twice, including with one thread, but the oxlint process panicked inside oxc_allocator; typecheck, tests, formatting, and workflow parsing all pass.

Generated with GPT-5 in the Codex harness.