[D06] compare_clt_fea.py: Table + Chart ✅ CHECKPOINT 1

[Siddardth7]

Due: April 1 | Day 6 of 14 — CHECKPOINT

• Add % error computation: abs(CLT - FEA) / FEA * 100 for deflection + σₓₓ
• Print formatted comparison table (metric | CLT | FEA | % error)
• Save table to data/fea_comparison.csv
• Generate side-by-side bar chart with % error annotation → save as figures/fea_comparison.png
• CHECKPOINT REVIEW: Is deflection error < 5%? Is σₓₓ error < 5%?
• Push clean commit with all Phase 1+2 work

✅ Done when: python compare_clt_fea.py outputs table + saves PNG. Both errors < 5%.