Fix dashboard local graph fallback

[stevesolun]

Summary

• keep dashboard graph neighborhoods functional when an installed local graph export is older than the packaged runtime graph
• preserve the packaged SQLite index mismatch guard, but fall back to the valid local graph.json instead of rendering an empty graph
• bump patch version to v1.0.11 and update changelog/docs release line

Validation

• python -m pytest src/tests/test_ctx_monitor.py src/tests/test_package_scaffold.py -q
• python -m ruff check src/ctx_monitor.py src/tests/test_ctx_monitor.py
• python -m mypy src
• uv run --python "C:\Program Files\Python311\python.exe" --with-requirements requirements-docs.txt mkdocs build --strict
• ctx-init --graph --model-mode skip
• dashboard /api/graph/github.json?type=mcp-server&limit=20 -> center mcp-server:github, 20 nodes, 19 edges, 1.14s