Six doc-comments on `OtelConfig` fields stated defaults that disagreed
with the constants the runtime actually applies in
`extract_otel_config_from_env`. Correct them to match:
- profiling_export_enabled: false -> true (DEFAULT_OBS_PROFILING_EXPORT_ENABLED)
- sample_ratio: 0.1 -> 1.0 (SAMPLE_RATIO)
- meter_interval: 15 -> 30 (METER_INTERVAL)
- logger_level: info -> error (DEFAULT_LOG_LEVEL)
- log_rotation_time: daily -> hourly (DEFAULT_LOG_ROTATION_TIME), and
document the full minutely/hourly/daily set plus the daily fallback
- log_cleanup_interval_seconds: 21600 -> 1800 (DEFAULT_OBS_LOG_CLEANUP_INTERVAL_SECONDS)
Doc-comment only; no behavior change.
