Add Cronicle-driven cron jobs with local migration workflow

Adds a new cron blueprint with UUID-keyed jobs that Cronicle triggers via
HTTP POST with a shared secret header. Also adds scripts/migrate-new.sh so
migrations can be generated locally against a Docker postgres when no prod
container is running.

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

scripts/migrate-new.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+# Generate a new aerich migration.
+# If a raggr container is running, exec into it.
+# Otherwise, spin up the local postgres service and run aerich from the venv.
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+# Load .env so POSTGRES_* vars are available locally
+if [ -f .env ]; then
+    set -a
+    # shellcheck disable=SC1091
+    source .env
+    set +a
+fi
+
+POSTGRES_USER="${POSTGRES_USER:-raggr}"
+POSTGRES_PASSWORD="${POSTGRES_PASSWORD:-changeme}"
+POSTGRES_DB="${POSTGRES_DB:-raggr}"
+LOCAL_DB_URL="postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@localhost:5432/${POSTGRES_DB}"
+
+read -rp "Migration name: " name
+
+RUNNING=$(docker compose ps --status running --services 2>/dev/null | grep -oE 'raggr-(blue|green)' | head -1 || true)
+
+if [ -n "$RUNNING" ]; then
+    echo "==> Using running container: $RUNNING"
+    docker compose --profile blue --profile green exec "$RUNNING" aerich migrate --name "$name"
+else
+    echo "==> No raggr container running — using local postgres"
+    docker compose up -d postgres
+
+    echo "==> Waiting for postgres to be ready..."
+    until docker compose exec -T postgres pg_isready -U "$POSTGRES_USER" > /dev/null 2>&1; do
+        sleep 1
+    done
+
+    echo "==> Applying existing migrations..."
+    DATABASE_URL="$LOCAL_DB_URL" .venv/bin/aerich upgrade
+
+    echo "==> Generating migration: $name"
+    DATABASE_URL="$LOCAL_DB_URL" .venv/bin/aerich migrate --name "$name"
+fi