refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

frontend/hooks/use-controlled-state.tsx

@@ -0,0 +1,42 @@
+import * as React from 'react';
+
+interface CommonControlledStateProps<T> {
+  value?: T;
+  defaultValue?: T;
+}
+
+/**
+ * 受控状态 Hook
+ * 用于处理受控和非受控组件的状态管理
+ * 
+ * @example
+ * ```tsx
+ * const [value, setValue] = useControlledState({ value: propValue, onChange: console.log })
+ * ```
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function useControlledState<T, Rest extends any[] = []>(
+  props: CommonControlledStateProps<T> & {
+    onChange?: (value: T, ...args: Rest) => void;
+  },
+): readonly [T, (next: T, ...args: Rest) => void] {
+  const { value, defaultValue, onChange } = props;
+
+  const [state, setInternalState] = React.useState<T>(
+    value !== undefined ? value : (defaultValue as T),
+  );
+
+  React.useEffect(() => {
+    if (value !== undefined) setInternalState(value);
+  }, [value]);
+
+  const setState = React.useCallback(
+    (next: T, ...args: Rest) => {
+      setInternalState(next);
+      onChange?.(next, ...args);
+    },
+    [onChange],
+  );
+
+  return [state, setState] as const;
+}