perf: optimize login transition and dashboard loading performance

docs: comprehensive README, fix delete button (204), retry on any status

feat: auto-detect document type from file extension

fix: use started_at instead of created_at on WorkflowRun

feat: retry failed docs, graceful shutdown, optimistic approve, timeline fix, dashboard latest workflow

feat: complete end-to-end platform with all standout behaviors

feat: add LLM-powered knowledge extraction workflow

Build workflow execution foundation

Initial project foundation