Keep the successful render path synchronous and allocation-light

[ricardo-devis-agullo]

Summary

• make warm environment cache hits synchronous (lookupEnv tri-state callback) so cached renders stop suspending through a discarded promise/microtask
• hoist stable callback adapters per registry render service: repository getComponent, nested renderer bound to the registry conf, and fromPromise adapters for renderComponent/renderComponents
• build component-retrieved telemetry only at completion when a listener exists (one scalar hrtime.bigint() start timestamp; no payload allocation, end-clock read, or fire when unobserved), preserving mid-flight listener add/remove semantics
• remove the top-level async from the callback renderer and make normal returnComponent completion synchronous; move local source-map/stack enrichment into a cold async helper that still finishes enrichment before the public callback and falls back to the original stack on failure
• delete the now-unused get-component-retrieving-info.ts; add frame?: string to the response details type to match runtime behavior

Preserved invariants: exact-once completion, timeout cleanup before event/callback, Domain execution, ENV_RESOLVING_ERROR / DATA_RESOLVING_ERROR behavior, single-flight storage reads, and renderer-return → provider → event → callback ordering. The only timing change is removal of an internal warm-env microtask.

Benchmarks (same machine, clean-tree baseline vs this branch)

• burst: deterministic storage work counts unchanged (1 read each for package/env/provider/template at N=50 and N=200); CPU user time 17ms→17ms (N=50) and ~30ms (N=200)
• quick: local-memory 6286→7166 rps (+14%), p95 20.1→17.9ms; storage-simulated +14%; batch-storage 1040→1265 rps (+22%), p95 103→86ms
• high-load: high-load-local 6050→7119 rps (+18%), p95 38.4→32.2ms; high-load-storage 5651→6363 rps (+13%), p95 40.0→35.7ms
• gates: exit 0 with --max-rps-regression-percent=5 --max-p95-regression-percent=5 --expect-success-rate=1

Test plan

• new characterization suite registry-routes-helpers-get-component-timing.js: renderer-return-before-callback trace with microtask sentinel, repo→env→provider gating, sync throw / async success-failure / double-callback exact-once, timeout cleanup ordering, retrieval payload key parity (success + error), local enrichment ordering and fallback, warm env hit without a second repository env lookup, real-events-handler mid-flight listener add/remove
• existing helper suites updated for the hasListeners contract
• npm --workspace packages/oc run build
• npm --workspace packages/oc run test-silent (1052 passing)
• npm --workspace packages/oc run bench:burst
• quick and high-load comparison commands against same-machine baselines

Closes plan 006 in plans/README.md.