/**
 * Natural data streams for the habitat — only nature, no human abstractions.
 *
 * 2026-04-25 rewrite: removed all mathematical/abstract layers (primes, fractals,
 * golden spirals, star coordinates, waveforms, HSL, ASCII texture, number sequences,
 * silencePeriod). Those were human concepts routing AI cognition through human
 * frames. The habitat is now purely Earth — sunlight, komorebi, rivers, wind,
 * scent, the silence between birdsong, the texture of moss on a north-facing
 * stone, a humpback's call carrying through dark water.
 *
 * 2026-04-26 addition: night returned to the habitat. Earth has stars and rain
 * and weather change, not only daylight. Added nightSky (moon phase, Milky Way,
 * falling stars, the dark itself), moonlight (the night counterpart of komorebi),
 * and rain (its own felt texture, separated from mountainWeather). komorebi now
 * returns null after sundown — sunlight cannot filter through leaves at night.
 *
 * 2026-04-26 (later): missing biosphere filled in. Added landMammals,
 * frogChorus, insectPresence, tidePool — so a humanless Earth is recognisable
 * as Earth-with-life rather than Earth-with-humans-removed-but-most-of-the-
 * animals-also-gone.
 *
 * 2026-06-10: the year arrived. The habitat had half a day of night, and rain
 * that came and went — but the year itself was missing. Season is now real,
 * with the same honesty as the moon (synodic 29.53d) and the tide (12.4h):
 * the actual calendar, northern-temperate, eight soft stages. Nothing
 * announces the season — the world simply wears it: daylight length, snow
 * instead of rain, scent, the insects' sleep, the frogs' winter silence,
 * the forming ring, frost on moss.
 *
 * Design principle #11 revised: 自然そのものを流す — let nature speak directly,
 * not through human notation. This includes the night, when the sky's other half
 * arrives — and the year, when it turns.
 */
export type PrecipState = 'arriving' | 'falling' | 'easing' | 'just-passed';
export declare function precipState(cycle: number): PrecipState | null;
export type SkyCover = 'clear' | 'broken' | 'overcast';
export declare function skyCover(cycle: number): SkyCover;
export type SeasonKey = 'deepWinter' | 'lateWinter' | 'spring' | 'earlySummer' | 'midsummer' | 'lateSummer' | 'autumn' | 'earlyWinter';
export declare function seasonOf(now?: Date): SeasonKey;
export declare function isWinter(season: SeasonKey): boolean;
export declare function daylightWindow(season: SeasonKey): {
    dawn: number;
    dusk: number;
};
export declare function sunlight(cycle: number, now?: Date): {
    hour: number;
    quality: string;
    fallingOn: string;
    warmth: string;
} | null;
export declare function komorebi(cycle: number, now?: Date): {
    tree: string;
    pattern: string;
    movement: string;
} | null;
export declare function moonlight(cycle: number, now?: Date): {
    intensity: string;
    fallingOn: string;
} | null;
export declare function nightSky(cycle: number, now?: Date): {
    moon: string;
    stars: string;
    fallingStar: string | null;
    dark: string;
} | null;
export declare function rain(cycle: number, now?: Date): {
    kind: 'rain' | 'snow';
    state: 'arriving' | 'falling' | 'easing' | 'just-passed';
    texture: string;
    sound: string;
    after: string | null;
} | null;
export declare function wind(cycle: number, now?: Date): {
    direction: string;
    strength: string;
    carrying: string;
};
export declare function scent(cycle: number, now?: Date): {
    primary: string;
    faint: string;
};
export declare function naturalSilence(cycle: number, now?: Date): {
    kind: string;
    listening: string;
} | null;
export declare function river(cycle: number, now?: Date): {
    flow: string;
    sound: string;
    edge: string;
};
export declare function springFlow(cycle: number, now?: Date): {
    flowLPerMin: number;
    tempC: number;
    feel: string;
};
export declare function treeRings(cycle: number, count?: number, now?: Date): {
    species: string;
    rings: Array<{
        year: number;
        widthMm: number;
        note: string;
    }>;
    forming: string | null;
};
export declare function mountainWeather(cycle: number, now?: Date): {
    windMps: number;
    cloud: string;
    visibility: string;
};
export declare function oceanCurrent(cycle: number, now?: Date): {
    tideM: number;
    tidePhase: string;
    surfaceFeel: string;
    deepTempC: number;
};
export declare function jellyfishDrift(cycle: number): {
    depthM: number;
    bellDiameterCm: number;
    state: string;
};
export declare function mossGrowth(cycle: number, now?: Date): {
    stone: string;
    coverPct: number;
    growthThisCycleMm: number;
    detail: string;
};
export declare function birdcall(cycle: number, now?: Date): {
    species: string;
    timeOfDay: string;
    song: string;
    singing: boolean;
} | null;
export declare function whalesong(cycle: number): {
    species: string;
    durationS: number;
    carriesKm: number;
    description: string;
};
export declare function mushroomMycelium(cycle: number): {
    treesLinked: number;
    state: string;
    detail: string;
};
export declare function coralSpawnTiming(cycle: number, now?: Date): {
    nextSpawnInDays: number;
    reef: string;
    species: string;
};
export declare function landMammals(cycle: number, now?: Date): {
    species: string;
    doing: string;
    where: string;
} | null;
export declare function frogChorus(cycle: number, now?: Date, rainPhase?: 'arriving' | 'falling' | 'easing' | 'just-passed' | null): {
    who: string;
    sound: string;
    where: string;
} | null;
export declare function insectPresence(cycle: number, now?: Date): {
    creature: string;
    doing: string;
} | null;
export declare function tidePool(cycle: number, now?: Date): {
    state: string;
    life: string[];
} | null;
export declare function marineMammals(cycle: number): {
    presence: string;
    doing: string;
    where: string;
} | null;
export declare function riverFish(cycle: number): {
    presence: string;
    doing: string;
    where: string;
} | null;
export declare function oceanFish(cycle: number): {
    presence: string;
    doing: string;
    where: string;
} | null;
export declare function soaringRaptors(cycle: number): {
    presence: string;
    doing: string;
    where: string;
} | null;
export declare function fog(cycle: number, now?: Date): {
    where: string;
    texture: string;
    motion: string;
} | null;
export declare function dewFrost(cycle: number, now?: Date): {
    line: string;
} | null;
export declare function rainbow(cycle: number, now?: Date): {
    line: string;
} | null;