Add drawer menu with flat structure, unified panel styling, Room/SQLCipher setup

app/src/main/java/com/mistral/chat/data/SettingDao.kt

@@ -0,0 +1,22 @@
+package com.mistral.chat.data
+
+import androidx.room.*
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface SettingDao {
+    @Query("SELECT * FROM settings WHERE `key` = :key")
+    suspend fun getSetting(key: String): Setting?
+    
+    @Query("SELECT value FROM settings WHERE `key` = :key")
+    suspend fun getValue(key: String): String?
+    
+    @Query("SELECT value FROM settings WHERE `key` = :key")
+    fun getValueFlow(key: String): Flow<String?>
+    
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insert(setting: Setting)
+    
+    @Query("DELETE FROM settings WHERE `key` = :key")
+    suspend fun delete(key: String)
+}