feat: increase max dialog rounds, web search summary, and bug fixes

[limityan]

Summary

This PR includes 4 commits that add new features and fix several bugs across the agent runtime, web search UI, and frontend styling.

Changes

Features

• Increase max dialog rounds to 200 with soft limit continuation

  • Increase default max_rounds from 50 to 200 in ExecutionEngineConfig
  • Add max_rounds field to AIConfig (user-configurable)
  • Read max_rounds from config in all execution entry points (desktop, server, core system)
  • Add "Continue" button in frontend when max rounds is reached
  • Add continueDialogTurn to FlowChatManager
  • Update i18n strings for en-US, zh-CN, zh-TW

• Web search: support displaying summary when no search results

  • Add summary rendering in WebSearchCard when results are empty
  • Add i18n keys for summary availability in en-US, zh-CN, zh-TW
  • Refactor expandable logic to include summary-only state

Bug Fixes

• Handle git diff args starting with -- separator

  • When model passes args like -- file1 file2 (no leading space before --), the previous parser failed to find the -- separator and treated all file paths as a single commit ref, causing "unknown revision" error
  • Add an explicit branch to detect -- prefix directly

• Fix inline-code color overriding link color in light theme

  • Correct CSS specificity so inline <code> elements no longer override link colors in light theme

Files Changed (27 files, +277 / -43)

Area	Key Files
Agent runtime	execution_engine.rs, system.rs, git_tool.rs, config/types.rs
Desktop / Server	desktop/src/lib.rs, server/src/bootstrap.rs
Frontend	WebSearchCard.tsx, ModernFlowChatContainer.tsx, VirtualItemRenderer.tsx, FlowChatManager.ts, SessionConfig.tsx
Styles	Markdown.scss, FlowTextBlock.scss, VirtualItemRenderer.scss, ModelThinkingDisplay.scss
i18n	en-US, zh-CN, zh-TW locale files for errors, flow-chat, and session-config