chore: bump version to 0.3.4

[chenyme]

✨ Feature

• Added full-text conversation search across titles, labels, projects, metadata, and message content, with matched-message previews.
• Added manual conversation label management and an option to disable automatic label generation to reduce auxiliary token usage.
• Added bulk project moves for selected conversations.
• Added Markdown composer preview, rich-text-to-Markdown paste, inline code copying, and improved code-block presentation.
• Added configurable OpenAI prompt caching with automatic, implicit, and explicit modes, plus TTL and retention controls.
• Added quick-fill upstream headers for conversation IDs, session keys, request IDs, and OpenAI diagnostic identifiers.
• Added post-settlement account balances to user and administrator usage logs.
• Added detailed conversation trace inspection and batch trace cleanup for administrators without removing messages, attachments, or billing records.

⚡ Optimization

• Added automatic failover across up to three eligible upstream routes for timeouts, rate limits, server errors, and network failures.
• Preserved historical images across multi-turn conversations for more reliable visual context.
• Expanded reasoning-context compatibility for DeepSeek, Moonshot, Zhipu, Xiaomi MiMo, Alibaba Qwen, MiniMax, and OpenRouter-compatible routes.
• Added configurable MCP metadata synchronization, allowing administrators to preserve local tool names and descriptions or replace them with server values.
• Standardized file-size settings in MB, aligned the default full-context limit to 2 MB, and improved attachment-limit messages.
• Prevented large file contents from bloating conversation traces and the administrator log viewer.
• Deferred conversation creation until the first message is sent, preventing empty conversations from appearing.
• Improved chat scrolling, streaming layout stability, generation recovery, and model-menu sizing on constrained displays.

🐛 Fixed

• Fixed failed turns disappearing when the account balance is insufficient.
• Fixed interrupted generations losing reasoning content or producing incomplete usage settlement.
• Fixed conversation titles being lost after the first generation was stopped or failed.
• Fixed concurrent generations, queued messages, and resumed streams leaking between conversation branches.
• Fixed negative account balances being displayed incorrectly.
• Fixed Gemini text-only responses and MCP tools losing referenced JSON Schema definitions.
• Fixed OpenAI prompt-cache history, rolling breakpoints, relay-specific boundaries, and cross-turn affinity.
• Fixed long conversation-search queries returning unclear errors.
• Fixed mobile Markdown table overflow, empty Markdown links, and unwanted trailing newlines in copied code blocks.
• Fixed PWA orientation behavior so installed apps respect the device’s system rotation lock.