feat: redesign Dashboard with 2-view split and improved UX

fix: support settings endpoint without trailing slash

fix: support plugins endpoint without trailing slash

feat: add static file serving and improve UI/UX design

test: add comprehensive API and core module tests

fix: add list_providers method and agents list endpoint

chore: add test_models package init

fix: replace deprecated datetime.utcnow with timezone-aware

feat: register settings and plugins API routes

feat: add modular plugin system for extensions

feat: add client API key configuration and model selection

test: add comprehensive backend test suite

feat: add API routes and utility modules

feat: add MCP tool registry and search engine integration

feat: implement hierarchical memory system

feat: add multi-model LLM router with providers

feat: implement multi-agent system with coordinator

feat: add core RL environment models (observation, action, reward, env)

chore: initialize backend project structure with FastAPI