Add onboarding screen for first-time users

- Show welcome view when no project is selected
- Explain the Research → Plan → Implement workflow
- Include ANTHROPIC_API_KEY setup instructions
- List getting started steps (add project, create session, describe work)
- Explain iteration workflow with Review/Submit buttons
- Add CSS styling for onboarding content

1 files changed, 1 insertions, 0 deletions

diff --git a/renderer/src/App.tsx b/renderer/src/App.tsx
index 22082a2..d5a2efd 100644
--- a/renderer/src/App.tsx
+++ b/renderer/src/App.tsx
@@ -256,6 +256,7 @@ export function App() {
           onChange={setDocumentContent}
           phase={selectedSession?.phase || "research"}
           disabled={!selectedSession || selectedSession.phase === "implement"}
+          showOnboarding={!selectedProject}
         />
 
         <ChatPane