feat: consolidate settings into unified Settings Hub with tabs
- Create Settings Hub with 6 tabs: General, Models, Prompts, Tools, Knowledge, Memory
- Extract page content into reusable tab components:
- GeneralTab: appearance, chat defaults, shortcuts, about
- ModelsTab: local models, ollama.com browser, pull/create
- PromptsTab: my prompts, browse templates
- ToolsTab: built-in and custom tools with enhanced UI
- KnowledgeTab: RAG document management
- MemoryTab: embedding model, auto-compact, model parameters
- Add SettingsTabs navigation component with icons
- Consolidate sidebar from 5 links to single Settings link
- Add 301 redirects for old URLs (/models, /prompts, /tools, /knowledge)
- Upgrade Tools tab with stats bar, search, tool icons, and parameter badges
vikingowl
245526af99