Before: the local otel-collector exported every pipeline to `debug`
(stdout) only, and the jaeger box's OTLP receiver wasn't host-mapped or
fed by anything. Net result — the Jaeger UI at :26686 was always empty;
traces sent to the collector died at the debug exporter. (Flagged in
review by DorianZheng.)

Fix (option a — keep the collector in the path for prod parity):
- SPEC_JAEGER: host-map jaeger's OTLP gRPC receiver (26687 → box :4317).
  jaeger 1.67 all-in-one already has COLLECTOR_OTLP_ENABLED=true.
- _OTEL_CONFIG → _otel_config(cfg): add an `otlp/jaeger` exporter
  (host.boxlite.internal:26687, tls insecure) and add it to the
  *traces* pipeline alongside debug. metrics/logs stay debug-only
  (Jaeger doesn't ingest them).
- SPEC_OTEL: depends_on=["jaeger"] so the export target is up first.

Verified end-to-end on a live stack: POST an OTLP/HTTP trace to the
collector (:24318) → within 2s the Jaeger query API returns the service
and the trace. 35 unit tests pass (topo sort handles the new
otel→jaeger edge).

Docs updated (README §Known-limitations #2, CONNECTIONS §6/§8) — the
"Jaeger pipeline not connected" limitation is removed; the remaining
gap is only the custom boxlite_exporter build (ClickHouse/api push-back).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

5-service stack: pg (Phase 2) + redis/minio/minio-init/registry (3a).
Introduces http_url healthcheck, one_shot lifecycle, repo_root resolution.
Closes Phase-2 debt #1 (narrow start_service exception); defers debt #2
and tcp_port (no caller in 3a). Autonomous execution per /goal directive.

…#2)

Before: the local otel-collector exported every pipeline to `debug`
(stdout) only, and the jaeger box's OTLP receiver wasn't host-mapped or
fed by anything. Net result — the Jaeger UI at :26686 was always empty;
traces sent to the collector died at the debug exporter. (Flagged in
review by DorianZheng.)

Fix (option a — keep the collector in the path for prod parity):
- SPEC_JAEGER: host-map jaeger's OTLP gRPC receiver (26687 → box :4317).
  jaeger 1.67 all-in-one already has COLLECTOR_OTLP_ENABLED=true.
- _OTEL_CONFIG → _otel_config(cfg): add an `otlp/jaeger` exporter
  (host.boxlite.internal:26687, tls insecure) and add it to the
  *traces* pipeline alongside debug. metrics/logs stay debug-only
  (Jaeger doesn't ingest them).
- SPEC_OTEL: depends_on=["jaeger"] so the export target is up first.

Verified end-to-end on a live stack: POST an OTLP/HTTP trace to the
collector (:24318) → within 2s the Jaeger query API returns the service
and the trace. 35 unit tests pass (topo sort handles the new
otel→jaeger edge).

Docs updated (README §Known-limitations #2, CONNECTIONS §6/§8) — the
"Jaeger pipeline not connected" limitation is removed; the remaining
gap is only the custom boxlite_exporter build (ClickHouse/api push-back).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>