Store the per-account gateway endpoint as {domain, proxy_address} with a
global unique index on the full hostname; dedicated = (domain ==
proxy_address). Bootstrap becomes an explicit POST carrying exactly one
of proxy_address (server allocates an adjective-noun label beneath it)
or endpoint (claimed verbatim, address-first); provider create loses its
bootstrap side effect. PUT is a full replace with every field required —
the immutable identity fields must be echoed unchanged and a mismatch is
rejected with 422. A guarded DELETE releases the endpoint: refused with
412 while providers exist or a proxy is actively serving the endpoint
hostname (matched case-insensitively); re-creating bootstraps fresh. A
self-addressed pin excludes its address from the account's cluster allow
list, and the live mapping update path now addresses the serving proxy
from the synthesized service. Existing rows are migrated on all three
store engines.
## Describe your changes
The model-allowlist guardrail was merged into one account-wide union and
enforced flat on every request, ignoring which policy/group/provider
authorised it. With multiple policies — especially a mix of guardrailed
and un-guardrailed ones — this caused:
- **false-allow**: a model allowlisted for one group/provider leaked to
any caller; and
- **false-deny**: an un-guardrailed policy (intended unrestricted) was
blocked by another policy's allowlist.
Enforcement is now policy/group-aware, mirroring `llm_limit_check`:
- **Management (`SelectPolicyForRequest`) is authoritative.** It uses
the request model (already carried in
`CheckLLMPolicyLimitsRequest.model`, previously ignored) to keep only
applicable policies whose guardrails permit the model; no
allowlist-enabled guardrail = unrestricted. Denies
`llm_policy.model_blocked` when policies govern the (provider, groups)
but none permits the model.
- **Proxy `llm_guardrail` becomes a per-provider fail-closed backstop.**
The synthesiser emits an allowlist only for providers every authorising
policy restricts; the middleware keys off the resolved provider id and
keeps unknown-model fail-closed.
