fix: ChatBubble crash and DeepSeek API compatibility

- Fix ChatBubble to handle non-string content with String() wrapper
- Fix API route to use generateText for non-streaming requests
- Add @ai-sdk/openai-compatible for non-OpenAI providers (DeepSeek, etc.)
- Use Chat Completions API instead of Responses API for compatible providers
- Update ChatBubble tests and fix component exports to kebab-case
- Remove stale PascalCase ChatBubble.tsx file

_bmad/bmb/workflows/workflow/templates/minimal-output-template.md

@@ -0,0 +1,11 @@
+---
+stepsCompleted: []
+lastStep: ''
+date: ''
+user_name: ''
+project_name: ''
+---
+
+# {{document_title}}
+
+[Content will be progressively appended by workflow steps]