Enable automatic web search by default; improve toggle behavior and search planning.

src/db/chatRepository.js

@@ -111,6 +111,7 @@ export function createChatStatements(db) {
             LIMIT 1
         `),
         updateChatSessionTitle: db.prepare("UPDATE chat_sessions SET title = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
+        updateChatUserPersona: db.prepare("UPDATE chat_sessions SET user_persona_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
         updateChatSessionScene: db.prepare("UPDATE chat_sessions SET scenario_prompt = ?, scenario_summary = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
         updateChatContextSummary: db.prepare("UPDATE chat_sessions SET context_summary = ?, context_summary_message_id = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ? AND username = ?"),
         updateChatGenerationSettings: db.prepare(`
@@ -432,6 +433,7 @@ const failChatTurnTransaction = db.transaction((chatId, userMessageId, errorMess
             return statements.getChatSession.get(chatId, username);
         },
         updateChatTitle: (chatId, username, title) => statements.updateChatSessionTitle.run(title, chatId, username),
+        updateChatUserPersona: (chatId, username, personaId) => statements.updateChatUserPersona.run(personaId ?? null, chatId, username),
         updateChatScene: (chatId, username, scenarioPrompt, scenarioSummary) => statements.updateChatSessionScene.run(scenarioPrompt, scenarioSummary, chatId, username),
         updateChatContextSummary: (chatId, username, summary, messageId) => statements.updateChatContextSummary.run(summary, Number(messageId || 0), chatId, username),
         getPersonaChatState: (chatId, username) => statements.getPersonaChatState.get(chatId, username) || null,