Add comprehensive Material Symbols analysis and recommendations

- Complete technical analysis of icon font issues
- Detailed explanation of ligature-based fonts vs SVG icons
- Performance comparison and file size analysis
- Recommendation to migrate to Heroicons (SVG-based)
- Implementation plan for migration
- Decision matrix comparing all options

Key findings:
- Current font solution: 3.7 MB (32x larger than target)
- Subsetting ligature fonts provides no benefit
- SVG icons (Heroicons) would be 91% smaller (~150 KB)
- Migration would improve page load time by 2-3 seconds on 3G

See docs/material-symbols-complete-analysis.md for full details.

Author: etewiah