[D3-03] Build evidence-linked research writing workspace

[dkritarth]

Outcome

Draft research notes/synthesis with AI assistance while keeping claims linked to paper evidence and user in control.

Dependencies

Blocked by #44.

Scope

Local editor, explicit source context, agent-assisted outline/rewrite/critique, evidence links, autosave/version safety, export. Not autonomous paper generation and not unsupported citation insertion.

Acceptance criteria

• Draft persists locally with recovery/version safety.
• AI operations show selected source context before run.
• Generated factual claims carry traceable evidence or explicit unsupported marker.
• User edits are never overwritten silently.
• Export preserves text and citations in documented format.
• Prompt injection inside papers is treated as content, not instruction.
• Accessibility and long-document performance remain usable.

Live verification

Create literature-review section from three papers, verify evidence links, edit during/after AI operation, simulate failure/restart, restore prior content, export and inspect artifact.

Required evidence

Focused PR uses Closes #45. Provide a written design first, failing tests/baseline, focused/full tests, typecheck, build, diff check, exact live Electron procedure, real-paper evidence, screenshots, console state, performance observations, and limitations. Independent reviewer repeats representative workflow.