// Package postgres documents weatherfeeder's PostgreSQL sink contract for
// downstream SQL consumers.
//
// This package wires weatherfeeder canonical events into normalized relational
// tables. Downstream consumers can reconstruct the same canonical JSON objects
// that were written by joining parent/child tables as described below.
//
// Canonical input schemas:
//   - weather.observation.v1 -> model.WeatherObservation
//   - weather.forecast.v1    -> model.WeatherForecastRun
//   - weather.alert.v1       -> model.WeatherAlertRun
//
// Parent/child relationships:
//   - observations.event_id -> observation_cloud_layers.event_id
//   - observations.event_id -> observation_present_weather.event_id
//   - forecasts.event_id    -> forecast_periods.run_event_id
//   - alert_runs.event_id   -> alerts.run_event_id
//   - alerts.(run_event_id, alert_index) -> alert_references.(run_event_id, alert_index)
//
// Dedupe and retention behavior:
//   - Parent primary keys (event_id): observations, forecasts, alert_runs.
//   - Child primary keys use positional indexes to preserve payload order.
//   - Prune columns:
//   - observations.observed_at
//   - observation_cloud_layers.observed_at
//   - observation_present_weather.observed_at
//   - forecasts.issued_at
//   - forecast_periods.issued_at
//   - alert_runs.as_of
//   - alerts.as_of
//   - alert_references.as_of
//
// Envelope field mapping (shared parent columns)
//
// These columns exist on observations, forecasts, and alert_runs:
//   - event_id TEXT -> event.id
//   - event_kind TEXT -> event.kind
//   - event_source TEXT -> event.source
//   - event_schema TEXT -> event.schema
//   - event_emitted_at TIMESTAMPTZ -> event.emitted_at
//   - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
//
// Table contract
//
//  1. observations (PK: event_id)
//
//     - event_id TEXT -> event.id
//     - event_kind TEXT -> event.kind
//     - event_source TEXT -> event.source
//     - event_schema TEXT -> event.schema
//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
//     - station_id TEXT NULL -> payload.stationId
//     - station_name TEXT NULL -> payload.stationName
//     - observed_at TIMESTAMPTZ -> payload.timestamp
//     - condition_code INTEGER -> payload.conditionCode
//     - condition_text TEXT NULL -> payload.conditionText
//     - is_day BOOLEAN NULL -> payload.isDay
//     - provider_raw_description TEXT NULL -> payload.providerRawDescription
//     - text_description TEXT NULL -> payload.textDescription
//     - icon_url TEXT NULL -> payload.iconUrl
//     - temperature_c DOUBLE PRECISION NULL -> payload.temperatureC
//     - dewpoint_c DOUBLE PRECISION NULL -> payload.dewpointC
//     - wind_direction_degrees DOUBLE PRECISION NULL -> payload.windDirectionDegrees
//     - wind_speed_kmh DOUBLE PRECISION NULL -> payload.windSpeedKmh
//     - wind_gust_kmh DOUBLE PRECISION NULL -> payload.windGustKmh
//     - barometric_pressure_pa DOUBLE PRECISION NULL -> payload.barometricPressurePa
//     - sea_level_pressure_pa DOUBLE PRECISION NULL -> payload.seaLevelPressurePa
//     - visibility_meters DOUBLE PRECISION NULL -> payload.visibilityMeters
//     - relative_humidity_percent DOUBLE PRECISION NULL -> payload.relativeHumidityPercent
//     - apparent_temperature_c DOUBLE PRECISION NULL -> payload.apparentTemperatureC
//     - elevation_meters DOUBLE PRECISION NULL -> payload.elevationMeters
//     - raw_message TEXT NULL -> payload.rawMessage
//
//  2. observation_cloud_layers (PK: event_id, layer_index)
//
//     - event_id TEXT -> observations.event_id / payload.cloudLayers[i]
//     - layer_index INTEGER -> i (array position in payload.cloudLayers)
//     - observed_at TIMESTAMPTZ -> payload.timestamp
//     - base_meters DOUBLE PRECISION NULL -> payload.cloudLayers[i].baseMeters
//     - amount TEXT NULL -> payload.cloudLayers[i].amount
//
//  3. observation_present_weather (PK: event_id, weather_index)
//
//     - event_id TEXT -> observations.event_id / payload.presentWeather[i]
//     - weather_index INTEGER -> i (array position in payload.presentWeather)
//     - observed_at TIMESTAMPTZ -> payload.timestamp
//     - raw_text TEXT NULL -> JSON-encoded payload.presentWeather[i].raw
//
// Note: raw_text stores compact JSON text. Consumers that need the original
// object should parse raw_text as JSON.
//
//  4. forecasts (PK: event_id)
//
//     - event_id TEXT -> event.id
//     - event_kind TEXT -> event.kind
//     - event_source TEXT -> event.source
//     - event_schema TEXT -> event.schema
//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
//     - location_id TEXT NULL -> payload.locationId
//     - location_name TEXT NULL -> payload.locationName
//     - issued_at TIMESTAMPTZ -> payload.issuedAt
//     - updated_at TIMESTAMPTZ NULL -> payload.updatedAt
//     - product TEXT -> payload.product
//     - latitude DOUBLE PRECISION NULL -> payload.latitude
//     - longitude DOUBLE PRECISION NULL -> payload.longitude
//     - elevation_meters DOUBLE PRECISION NULL -> payload.elevationMeters
//     - period_count INTEGER -> len(payload.periods)
//
//  5. forecast_periods (PK: run_event_id, period_index)
//
//     - run_event_id TEXT -> forecasts.event_id / payload.periods[i]
//     - period_index INTEGER -> i (array position in payload.periods)
//     - issued_at TIMESTAMPTZ -> payload.issuedAt (copied from parent)
//     - start_time TIMESTAMPTZ -> payload.periods[i].startTime
//     - end_time TIMESTAMPTZ -> payload.periods[i].endTime
//     - name TEXT NULL -> payload.periods[i].name
//     - is_day BOOLEAN NULL -> payload.periods[i].isDay
//     - condition_code INTEGER -> payload.periods[i].conditionCode
//     - condition_text TEXT NULL -> payload.periods[i].conditionText
//     - provider_raw_description TEXT NULL -> payload.periods[i].providerRawDescription
//     - text_description TEXT NULL -> payload.periods[i].textDescription
//     - detailed_text TEXT NULL -> payload.periods[i].detailedText
//     - icon_url TEXT NULL -> payload.periods[i].iconUrl
//     - temperature_c DOUBLE PRECISION NULL -> payload.periods[i].temperatureC
//     - temperature_c_min DOUBLE PRECISION NULL -> payload.periods[i].temperatureCMin
//     - temperature_c_max DOUBLE PRECISION NULL -> payload.periods[i].temperatureCMax
//     - dewpoint_c DOUBLE PRECISION NULL -> payload.periods[i].dewpointC
//     - relative_humidity_percent DOUBLE PRECISION NULL -> payload.periods[i].relativeHumidityPercent
//     - wind_direction_degrees DOUBLE PRECISION NULL -> payload.periods[i].windDirectionDegrees
//     - wind_speed_kmh DOUBLE PRECISION NULL -> payload.periods[i].windSpeedKmh
//     - wind_gust_kmh DOUBLE PRECISION NULL -> payload.periods[i].windGustKmh
//     - barometric_pressure_pa DOUBLE PRECISION NULL -> payload.periods[i].barometricPressurePa
//     - visibility_meters DOUBLE PRECISION NULL -> payload.periods[i].visibilityMeters
//     - apparent_temperature_c DOUBLE PRECISION NULL -> payload.periods[i].apparentTemperatureC
//     - cloud_cover_percent DOUBLE PRECISION NULL -> payload.periods[i].cloudCoverPercent
//     - probability_of_precipitation_percent DOUBLE PRECISION NULL -> payload.periods[i].probabilityOfPrecipitationPercent
//     - precipitation_amount_mm DOUBLE PRECISION NULL -> payload.periods[i].precipitationAmountMm
//     - snowfall_depth_mm DOUBLE PRECISION NULL -> payload.periods[i].snowfallDepthMm
//     - uv_index DOUBLE PRECISION NULL -> payload.periods[i].uvIndex
//
//  6. alert_runs (PK: event_id)
//
//     - event_id TEXT -> event.id
//     - event_kind TEXT -> event.kind
//     - event_source TEXT -> event.source
//     - event_schema TEXT -> event.schema
//     - event_emitted_at TIMESTAMPTZ -> event.emitted_at
//     - event_effective_at TIMESTAMPTZ NULL -> event.effective_at
//     - location_id TEXT NULL -> payload.locationId
//     - location_name TEXT NULL -> payload.locationName
//     - as_of TIMESTAMPTZ -> payload.asOf
//     - latitude DOUBLE PRECISION NULL -> payload.latitude
//     - longitude DOUBLE PRECISION NULL -> payload.longitude
//     - alert_count INTEGER -> len(payload.alerts)
//
//  7. alerts (PK: run_event_id, alert_index)
//
//     - run_event_id TEXT -> alert_runs.event_id / payload.alerts[i]
//     - alert_index INTEGER -> i (array position in payload.alerts)
//     - as_of TIMESTAMPTZ -> payload.asOf (copied from parent)
//     - alert_id TEXT -> payload.alerts[i].id
//     - event TEXT NULL -> payload.alerts[i].event
//     - headline TEXT NULL -> payload.alerts[i].headline
//     - severity TEXT NULL -> payload.alerts[i].severity
//     - urgency TEXT NULL -> payload.alerts[i].urgency
//     - certainty TEXT NULL -> payload.alerts[i].certainty
//     - status TEXT NULL -> payload.alerts[i].status
//     - message_type TEXT NULL -> payload.alerts[i].messageType
//     - category TEXT NULL -> payload.alerts[i].category
//     - response TEXT NULL -> payload.alerts[i].response
//     - description TEXT NULL -> payload.alerts[i].description
//     - instruction TEXT NULL -> payload.alerts[i].instruction
//     - sent TIMESTAMPTZ NULL -> payload.alerts[i].sent
//     - effective TIMESTAMPTZ NULL -> payload.alerts[i].effective
//     - onset TIMESTAMPTZ NULL -> payload.alerts[i].onset
//     - expires TIMESTAMPTZ NULL -> payload.alerts[i].expires
//     - area_description TEXT NULL -> payload.alerts[i].areaDescription
//     - sender_name TEXT NULL -> payload.alerts[i].senderName
//     - reference_count INTEGER -> len(payload.alerts[i].references)
//
//  8. alert_references (PK: run_event_id, alert_index, reference_index)
//
//     - run_event_id TEXT -> alert_runs.event_id / payload.alerts[i].references[j]
//     - alert_index INTEGER -> i (array position in payload.alerts)
//     - reference_index INTEGER -> j (array position in payload.alerts[i].references)
//     - as_of TIMESTAMPTZ -> payload.asOf (copied from parent)
//     - id TEXT NULL -> payload.alerts[i].references[j].id
//     - identifier TEXT NULL -> payload.alerts[i].references[j].identifier
//     - sender TEXT NULL -> payload.alerts[i].references[j].sender
//     - sent TIMESTAMPTZ NULL -> payload.alerts[i].references[j].sent
//
// Reconstructing canonical JSON payloads
//
//   - WeatherObservation:
//     read one row from observations, then join child rows by event_id ordered by
//     layer_index / weather_index to rebuild cloudLayers and presentWeather arrays.
//
//   - WeatherForecastRun:
//     read one row from forecasts, then join forecast_periods by run_event_id
//     ordered by period_index to rebuild periods.
//
//   - WeatherAlertRun:
//     read one row from alert_runs, join alerts by run_event_id ordered by
//     alert_index, then join alert_references by (run_event_id, alert_index)
//     ordered by reference_index to rebuild references per alert.
package postgres