-- Fleet automation: metric-driven rules. When a node's metric crosses a threshold
-- for a sustained window, fire an action (drain a hot node, bring one back, alert).
-- A null node_id applies the rule to every node in the workspace. Paired with the
-- metrics-aware placement (draining nodes stop receiving new agent workloads).
CREATE TABLE node_rules (
    id            UUID PRIMARY KEY,
    workspace_id  UUID NOT NULL REFERENCES workspaces (id) ON DELETE CASCADE,
    node_id       UUID REFERENCES nodes (id) ON DELETE CASCADE,
    name          TEXT NOT NULL,
    enabled       BOOLEAN NOT NULL DEFAULT true,
    metric        TEXT NOT NULL,             -- cpu_pct | mem_pct | disk_pct | gpu_pct | temp_max | load1
    op            TEXT NOT NULL,             -- '>' | '<' | '>=' | '<='
    threshold     DOUBLE PRECISION NOT NULL,
    for_seconds   INTEGER NOT NULL DEFAULT 60,
    action        JSONB NOT NULL,            -- {"type":"drain"|"undrain"|"alert"}
    last_fired_at TIMESTAMPTZ,
    created_at    TIMESTAMPTZ NOT NULL DEFAULT now()
);
CREATE INDEX node_rules_ws ON node_rules (workspace_id);