Text prompt and LLM output nodes need document-style editing without changing their existing node data contracts, so Markdown editing now writes back to the same prompt/outputText fields and Markdown files import as prompt nodes. Canvas shortcuts ignore local editors so document copy/paste remains native inside the modal.
Constraint: Preserve existing prompt and LLM node data contracts
Rejected: Replace inline prompt editing | would change current node interaction behavior
Confidence: high
Scope-risk: moderate
Directive: Keep canvas-level keyboard shortcuts out of modal and contentEditable targets
Tested: npm run test:run -- src/components/__tests__/PromptNode.test.tsx src/components/__tests__/WorkflowCanvas.test.tsx src/components/modals/__tests__/MarkdownEditorModal.test.tsx src/components/__tests__/FloatingNodeHeader.test.tsx src/components/__tests__/LLMGenerateNode.test.tsx
Tested: npm run build
Tested: git diff --check
Not-tested: npm run lint (existing Next 16 next lint path failure)