Add graceful error handling for incomplete GeoJSON during live editing

[deftio]

Problem

During live editing, incomplete GeoJSON content causes console errors as SquibView attempts to parse malformed JSON:

Error rendering GeoJSON: SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at t.value (squibview.js:1134:29)

This happens because the live editor processes content as users type, resulting in temporarily invalid JSON structures.

Expected Behavior

• GeoJSON parsing should fail gracefully without console errors
• Invalid JSON should display a helpful message instead of throwing errors
• Live editing experience should remain smooth

Proposed Solution

• Add try-catch blocks around JSON parsing in GeoJSON renderer
• Display helpful error states for invalid JSON
• Only attempt parsing when JSON appears structurally complete

Impact

• Better user experience during live editing
• Cleaner browser console
• More robust error handling

🤖 Generated with Claude Code

Co-Authored-By: Claude noreply@anthropic.com