feat: add initial database schema and postgres profile

src/main/resources/db/migration/h2/V1__init.sql

@@ -0,0 +1,32 @@
+CREATE TABLE app_user (
+    id            BIGINT       GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    username      VARCHAR(64)  NOT NULL,
+    password_hash VARCHAR(100) NOT NULL,
+    role          VARCHAR(16)  NOT NULL,
+    created_at    TIMESTAMP    NOT NULL,
+    CONSTRAINT uq_app_user_username UNIQUE (username)
+);
+
+CREATE TABLE resource (
+    id          BIGINT       GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    name        VARCHAR(128) NOT NULL,
+    description VARCHAR(512),
+    created_at  TIMESTAMP    NOT NULL,
+    version     BIGINT       NOT NULL DEFAULT 0
+);
+
+CREATE TABLE reservation (
+    id          BIGINT      GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    resource_id BIGINT      NOT NULL,
+    user_id     BIGINT      NOT NULL,
+    start_time  TIMESTAMP   NOT NULL,
+    end_time    TIMESTAMP   NOT NULL,
+    status      VARCHAR(16) NOT NULL,
+    created_at  TIMESTAMP   NOT NULL,
+    version     BIGINT      NOT NULL DEFAULT 0,
+    CONSTRAINT fk_reservation_resource FOREIGN KEY (resource_id) REFERENCES resource (id),
+    CONSTRAINT fk_reservation_user FOREIGN KEY (user_id) REFERENCES app_user (id)
+);
+
+CREATE INDEX idx_reservation_resource_status ON reservation (resource_id, status);
+CREATE INDEX idx_reservation_user ON reservation (user_id);