feat(database): adopt goose migrations (#62)

migrations/sql/002_task_framework.sql

@@ -0,0 +1,30 @@
+-- +goose Up
+-- +goose StatementBegin
+-- Execution history for completed task runs.
+CREATE TABLE task_executions (
+    id            BIGSERIAL PRIMARY KEY,
+    task_key      TEXT NOT NULL,
+    started_at    TIMESTAMPTZ NOT NULL,
+    completed_at  TIMESTAMPTZ NOT NULL,
+    status        TEXT NOT NULL,          -- 'completed', 'failed', 'cancelled'
+    error_message TEXT,
+    result_data   JSONB,                  -- task-specific summary
+    duration_ms   BIGINT NOT NULL
+);
+
+CREATE INDEX idx_task_executions_key_completed ON task_executions (task_key, completed_at DESC);
+
+-- User-configured trigger overrides.
+CREATE TABLE task_triggers (
+    id          BIGSERIAL PRIMARY KEY,
+    task_key    TEXT NOT NULL,
+    type        TEXT NOT NULL,             -- 'interval', 'daily', 'weekly', 'startup'
+    interval    BIGINT,                    -- milliseconds, for interval type
+    time_of_day TEXT,                      -- "HH:MM", for daily/weekly
+    day_of_week INT,                       -- 0-6, for weekly
+    max_runtime BIGINT,                    -- milliseconds, optional
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_task_triggers_key ON task_triggers (task_key);
+-- +goose StatementEnd