[codex] Normalize service telemetry rows

[philcunliffe]

What changed

• added OTLP protobuf ingestion for /v1/logs, /v1/traces, and /v1/metrics
• normalized the services/<service>/ browse tree to one JSON row per log record, span, or metric data point
• kept the top-level logs/, traces/, and metrics/ files as raw OTLP payload archives
• preserved logs-by-service/ as a compatibility mirror for normalized logs
• fixed the CLI to respect COLLECTIVUS_PORT and COLLECTIVUS_OUTPUT_DIR so launchd-managed desktop installs start cleanly
• migrated previously written raw services/<service>/*.jsonl files into normalized rows on startup and preserved the old raw envelopes under services-raw/

Why

The desktop and webapp now browse telemetry by service. That browse path needs per-entry rows, not raw OTLP envelopes, or the UI loses the single-row log shape and can’t treat traces and metrics consistently.

At the same time, Gas City and other OTLP/HTTP clients were sending protobuf payloads, which the collector previously rejected with 415 Unsupported Media Type.

User impact

• protobuf OTLP clients can now send logs, traces, and metrics to collectivus
• the Telemetry UI can browse services/<service>/logs-*.jsonl, traces-*.jsonl, and metrics-*.jsonl as normalized row-oriented files
• existing raw signal archives are still available under the top-level signal folders

Validation

• npm run lint
• npm test
• npm run typecheck
• live smoke-tested the launchd-managed listener on 127.0.0.1:4318