buzz/schema/tables/public/channel_members.sql

-- ── Channel members ───────────────────────────────────────────────────────────
-- Conformance: "Channels and channel membership". PK leads with community_id.

CREATE TABLE channel_members (
    community_id UUID NOT NULL REFERENCES communities(id),
    channel_id  UUID NOT NULL,
    pubkey      BYTEA NOT NULL,
    role        member_role NOT NULL DEFAULT 'member',
    joined_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    invited_by  BYTEA,
    removed_at  TIMESTAMPTZ,
    removed_by  BYTEA,
    hidden_at   TIMESTAMPTZ,
    PRIMARY KEY (community_id, channel_id, pubkey),
    FOREIGN KEY (community_id, channel_id)
        REFERENCES channels (community_id, id) ON DELETE CASCADE
);

CREATE INDEX idx_channel_members_pubkey ON channel_members (community_id, pubkey)
    WHERE removed_at IS NULL;