fix: Space filter bug and pulse directory location

[plur9]

Summary

• Fix space filter checkbox bug (complete rewrite with inclusion-based model)
• Fix pulse directory from relative pulses to .datacore/pulses
• Add title-based path finding (partial title match instead of full node IDs)
• Add debounce (300ms) to prevent rapid-fire filter requests

Changes

config/datacortex.yaml

• Changed pulse.directory from pulses (relative) to .datacore/pulses (keeps all state under .datacore/)

frontend/js/app.js

• Complete rewrite of filter model: inclusion-based (checked = included) instead of exclusion-based
• Added allSpaces/allTypes Sets to track available options
• Added findNodeByTitle() for partial title matching in path finder
• Added debounce utility to prevent rapid-fire API calls

Test plan

• Start server: datacortex serve
• Open http://localhost:8765
• Check/uncheck space filters - verify nodes update correctly
• Check/uncheck type filters - verify nodes update correctly
• Use path finder with partial titles (e.g., "fair data" instead of full node ID)
• Run datacortex pulse generate - verify saves to .datacore/pulses/

🤖 Generated with Claude Code