--demo-data + --connector claude-code: connector phase overwrites generated demo fixtures

[aiminnovations]

• Bug: When --demo-data and --connector claude-code are both passed, the demo data generator runs first and writes 55 entities + 133 relationships + 25 documents + 10 traces to data/fixtures.json. The connector then runs, finds 0 Claude Code data, and overwrites data/fixtures.json with {"entities": {}, "relationships": [], "documents": [], "traces": []}.
• Reproduction:

  PYTHONUTF8=1 PYTHONIOENCODING=utf-8 uvx --python 3.13 create-context-graph my-app \
    --domain software-engineering \
    --framework langgraph \
    --connector claude-code \
    --with-mcp \
    --mcp-profile extended \
    --demo-data \
    --output-dir /tmp/my-app
  

  Then inspect /tmp/my-app/data/fixtures.json -- it'll be 83 bytes of empty dict instead of ~96KB of demo data.
• Expected: connector should APPEND to existing fixtures.json (or merge), not REPLACE.
• Actual: connector overwrites.
• Workaround: separate generation runs -- generate once with --demo-data only, run connector separately afterward with make import (or skip connector).
• Environment: Windows 11, uvx 0.9.18, Python 3.13.11, create-context-graph (latest as of 2026-04-30).