Fix EdgeDraw reactivity to Python-side name changes (0.5.24)

[koaning]

What & why

Reported via r/marimo_notebook: adding/removing nodes on an EdgeDraw from Python did nothing. Two causes:

1. User-side (expected): widget.names.append(...) mutates in place, and traitlets only fires on reassignment — so it never syncs. Documented in the demo.
2. Real bug (fixed here): even with correct reassignment, the frontend read names only once at init and registered change handlers for links/directed but not names, so Python-side node changes never rendered.

Changes

• js/edgedraw.js (+ rebuilt wigglystuff/static/edgedraw.js): add a change:names handler that rebuilds nodes (reusing positions for survivors, spawning new ones at center), rebuilds the id maps, clears stale selection, prunes links pointing at removed nodes (and syncs them back to Python), re-binds the .node/.label selections keyed by id, and restarts the force simulation. Promoted the mutated closure bindings from const to let.
• demos/edgedraw.py: new "Editing nodes from Python" section (text box + Add/Remove buttons using reassignment) with a note on why .append() doesn't work. Bumped the PEP 723 pin to 0.5.24.
• Release: pyproject.toml / uv.lock → 0.5.24, CHANGELOG.md entry under ### Fixed.

Verification

• uv run pytest tests/test_edgedraw.py → 5 passed
• uv run marimo check demos/edgedraw.py → clean
• Smoke test: reassigning widget.names add/remove works; links preserved
• Manual: in the demo, Add node draws a draggable/linkable node; Remove node drops it and its edges

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