fix(cli): preserve Alexandria receipts and clarify retries
Summary
Alexandria executions now include an additive receipt containing actual reported credits, the client idempotency request ID, and the distinct server scrape ID. Print available charges and server IDs on stderr and preserve actionable status/code/action/retry metadata in failures.
Clarify that same-ID requests recover the same execution and replay completed results, including failures. Never automatically rotate an uncertain request ID.
Validation
TypeScript build and 35 focused tests passed. Three compact helper regressions cover receipt semantics, safe error serialization and retry-delay parsing; the existing compiled-CLI execution test verifies the receipt while retaining retry identity. No production calls.
Scope
Alexandria only. Ordinary URL scrape/search output, timeout, cache diagnostics and search --pretty were moved to draft #248. No API changes. This addresses the Alexandria portions of Exchange issues 548, 556 and CLI guidance in 544; it does not change server billing or replay semantics.