NDBC ocean observations
Added: noaa_marine_get_ocean_observations — NDBC .ocean sub-surface water-column data (temperature, conductivity, salinity, dissolved oxygen, chlorophyll, turbidity, pH, redox per reported depth); latest observation, one reading per depth; best-effort with a typed observations_not_found error (#16).
Changed: tsc-alias ^1.8.17 -> ^1.9.1 (dev).
Gates: devcheck clean (zero warnings), 117 tests, docker build+run verified, live field-tested against real NDBC.