[runtime] Instrument /verify path for chain-test triage

[GsCommand]

Motivation

• Add temporary, CI-visible diagnostics inside the /verify handler to determine whether the early cached-only schema guard is being hit and to localize where the failing chain test stalls (ENS resolution, crypto verify, or schema validation).

Description

• Add a top-of-handler console.error at /verify that emits wantSchema, wantEns, verb, VERIFY_SCHEMA_CACHED_ONLY, and the result of hasValidatorCached(verb).
• Add console.error("[verify] entering ENS resolution", { verb }) immediately before ENS resolution.
• Add console.error("[verify] entering crypto verify", { verb }) immediately before calling verifyReceiptEd25519Sha256.
• Add console.error("[verify] returning 202 validator_not_warmed_yet", { verb }) immediately before the early cached-only 202 return and console.error("[verify] entering schema validation path", { verb, cachedOnly, validatorCached }) before fetching/compiling the validator.

Testing

• Ran node --check server.mjs to validate syntax, which succeeded.

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Codex Task