update: integrate ics calendar

src/db/migrations/008_calendar_feeds.sql

@@ -0,0 +1,9 @@
+CREATE TABLE calendar_feeds (
+    id         SERIAL PRIMARY KEY,
+    person_id  INTEGER NOT NULL REFERENCES calendar_people(id) ON DELETE CASCADE,
+    label      TEXT,
+    ics_url    TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX idx_calendar_feeds_person_id ON calendar_feeds (person_id);