chore: 初始化仓库结构（.gitignore + data/ 占位）

- 排除 /target、/data、secret.bin、.env 等敏感与构建产物
- 保留 data/.gitkeep 占位以便运行时生成 bot.db / crypto.db

.gitignore

@@ -0,0 +1,33 @@
+# Rust build artifacts
+/target/
+**/*.rs.bk
+Cargo.lock.bak
+
+# Runtime data (bot 运行时生成)
+/data/
+!data/.gitkeep
+
+# Secrets
+*.pem
+*.key
+*.secret
+secret.bin
+
+# Editor
+.vscode/
+.idea/
+*.swp
+*.swo
+.DS_Store
+Thumbs.db
+
+# Environment
+.env
+.env.local
+
+# Logs
+*.log
+logs/
+
+# Cache
+.cache/

data/.gitkeep

@@ -0,0 +1 @@
+# placeholder so the directory is tracked even though contents are ignored