feat(dashboard): dashboard_layout table + repo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/db/migrations/012_dashboard_layout.sql

@@ -0,0 +1,10 @@
+-- 012_dashboard_layout.sql
+-- Single global, owner-scoped dashboard layout. One logical row keyed by a
+-- stable owner key (v2 is single-owner; 'owner' is the only key for now).
+CREATE TABLE dashboard_layout (
+  owner_key   text PRIMARY KEY DEFAULT 'owner',
+  card_order  jsonb NOT NULL DEFAULT '[]'::jsonb,   -- ["clock","weather",...]
+  hidden      jsonb NOT NULL DEFAULT '[]'::jsonb,   -- ["speedtest"]
+  sizes       jsonb NOT NULL DEFAULT '{}'::jsonb,   -- {"weather":"s"}
+  updated_at  timestamptz NOT NULL DEFAULT now()
+);

lib/db/repos/dashboard_layout.js

@@ -0,0 +1,24 @@
+import { pool } from '../pool.js';
+
+const DEFAULTS = { card_order: [], hidden: [], sizes: {} };
+
+export async function get() {
+  const { rows } = await pool.query(
+    `SELECT card_order, hidden, sizes FROM dashboard_layout WHERE owner_key = 'owner'`
+  );
+  return rows[0] || { ...DEFAULTS };
+}
+
+export async function put({ card_order = [], hidden = [], sizes = {} }) {
+  await pool.query(
+    `INSERT INTO dashboard_layout (owner_key, card_order, hidden, sizes, updated_at)
+     VALUES ('owner', $1::jsonb, $2::jsonb, $3::jsonb, now())
+     ON CONFLICT (owner_key) DO UPDATE
+       SET card_order = EXCLUDED.card_order,
+           hidden     = EXCLUDED.hidden,
+           sizes      = EXCLUDED.sizes,
+           updated_at = now()`,
+    [JSON.stringify(card_order), JSON.stringify(hidden), JSON.stringify(sizes)]
+  );
+  return get();
+}