Decide the passthrough-options policy: start-amqp's Record<string, unknown> bags are the only escape hatches

[btravers]

From the 2026-08-13 repo audit.

start-amqp is the only runtime with untyped passthrough options: connectionOptions?: Record<string, unknown> and defaultConsumerOptions?: Record<string, unknown> (packages/start-amqp/src/amqp-runtime.ts:43-44). Neither start-http (no ServerOptions passthrough) nor start-temporal (no WorkerOptions passthrough) has an equivalent.

unknown-shaped option bags cut against the typesafety pitch, and the asymmetry means the passthrough policy is accidental rather than decided.

Acceptance

• A decided policy: either every runtime gets a typed passthrough to its underlying library's options, or none does and the escape hatch is dropped.
• If kept, the two amqp bags take the underlying library's own option types instead of Record<string, unknown>.
• The policy recorded in the root CLAUDE.md for future runtimes.