[Electric 2.0] Cleanup Out-of-Date Examples

[KyleAMathews]

Goal

Remove or update examples that don't align with 2.0 story

Scope

• Audit /examples/ directory (20+ examples)
• Archive 1.0-style patterns that are superseded
• Update key examples to use TanStack DB
• Ensure all examples show "works with your stack" philosophy

Dependencies

New patterns documented

Acceptance Criteria

All public examples reflect 2.0 best practices

Context

Part of Electric 2.0 launch. Examples are critical for developer adoption - they need to showcase the best patterns.