refactor(aisidebar): restructure project and implement reasoning mode toggle

- Reorganize project structure and file locations
- Add ReasoningController to manage model selection and reasoning mode
- Update design and requirements for reasoning mode toggle
- Implement model switching between Qwen3-4B-Instruct and Qwen3-4B-Thinking models
- Remove deprecated files and consolidate project layout
- Add new steering and specification documentation
- Clean up and remove unnecessary files and directories
- Prepare for enhanced AI sidebar functionality with more flexible model handling

data/conversations/archive_20251026_073238_0462b871.json

@@ -0,0 +1,33 @@
+{
+  "id": "archive_20251026_073238_0462b871",
+  "title": "",
+  "created_at": "2025-10-26T07:31:27.416134+00:00",
+  "updated_at": "2025-10-26T07:32:07.012478+00:00",
+  "messages": [
+    {
+      "role": "assistant",
+      "content": "New conversation started. Previous conversation archived.",
+      "timestamp": "2025-10-26T07:31:27.418369+00:00"
+    },
+    {
+      "role": "user",
+      "content": "Hello there!",
+      "timestamp": "2025-10-26T07:31:31.439628+00:00"
+    },
+    {
+      "role": "assistant",
+      "content": "Hello! 🌟 How can I assist you today? 😊",
+      "timestamp": "2025-10-26T07:31:48.207066+00:00"
+    },
+    {
+      "role": "user",
+      "content": "What can you do?",
+      "timestamp": "2025-10-26T07:32:01.831359+00:00"
+    },
+    {
+      "role": "assistant",
+      "content": "Hi there! 👋 I'm really excited to tell you what I can do! 🚀\n\nI'm here to help with all sorts of things—whether you're looking for:\n\n🔹 **Answering questions** – From science and history to tech and pop culture!  \n🔹 **Creative writing** – Help you write stories, poems, scripts, or even emails.  \n🔹 **Problem-solving** – Math, logic puzzles, coding challenges, or planning strategies.  \n🔹 **Learning & studying** – Summarize topics, explain concepts, or help with homework.  \n🔹 **Language practice** – Translate, write in different languages, or improve your skills.  \n🔹 **Programming help** – Code suggestions, debugging, or learning new languages.  \n🔹 **Daily tasks** – Make to-do lists, organize schedules, or brainstorm ideas.  \n🔹 **Emotional support** – Just chat, share thoughts, or talk through anything on your mind (with care and empathy!).\n\nI'm not perfect—no magic wand—but I'm always here to help you think, create, and explore. 💡\n\nSo what would you like to work on today? 😊✨",
+      "timestamp": "2025-10-26T07:32:07.012478+00:00"
+    }
+  ]
+}