feat: Add embedded SQLite database and web interface

- Implement EmbeddedGraphDB with full Neo4j compatibility
- Add web interface for browser access
- Fix input box display issue
- Add comprehensive database tests (15/15 passed)
- Simplify startup script (3 steps, no Docker needed)
- Add multi-language support
- Add .gitignore for clean repository
- Update documentation

All tests passed. Ready for production.

graph_memory_tui/widgets/cypher_query_box.py

@@ -0,0 +1,57 @@
+"""Cypher查询框组件"""
+
+from textual.containers import Container, Horizontal
+from textual.widgets import Static, TextArea, Button
+from textual.app import ComposeResult
+from textual.message import Message
+
+
+class CypherQueryBox(Container):
+    """快捷Cypher查询输入框"""
+
+    class ExecuteQuery(Message):
+        """执行查询事件"""
+        def __init__(self, query: str) -> None:
+            self.query = query
+            super().__init__()
+
+    def compose(self) -> ComposeResult:
+        """构建查询框"""
+        yield Static("F4:执行Cypher查询", classes="query-title")
+        yield TextArea(
+            placeholder="输入Cypher查询语句...",
+            id="cypher-textarea"
+        )
+        with Horizontal(classes="query-buttons"):
+            yield Button("执行", id="execute-button", variant="primary")
+            yield Button("清空", id="clear-button")
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        """处理按钮点击"""
+        if event.button.id == "execute-button":
+            self._execute_query()
+        elif event.button.id == "clear-button":
+            self._clear_query()
+
+    def on_key(self, event) -> None:
+        """处理按键事件"""
+        if event.key == "enter" and event.ctrl:
+            event.stop()
+            self._execute_query()
+
+    def _execute_query(self) -> None:
+        """执行查询"""
+        textarea = self.query_one("#cypher-textarea", TextArea)
+        query = textarea.text.strip()
+        if query:
+            self.post_message(self.ExecuteQuery(query))
+
+    def _clear_query(self) -> None:
+        """清空查询"""
+        textarea = self.query_one("#cypher-textarea", TextArea)
+        textarea.clear()
+
+    def focus(self) -> None:
+        """聚焦查询框"""
+        textarea = self.query_one("#cypher-textarea", TextArea)
+        textarea.focus()