fix: proper layout centering, realistic stats, and GitHub Pages deployment

[XircTwerk]

Landing page:

• Rewrote layout with w-full + max-w-6xl mx-auto on every section — fixes content stuck to left edge on all viewport sizes
• Replaced fabricated stats ($2.8B, 847K deployments) with honest early-stage numbers: 1,240+ deployments, $840K+ revenue, 47 agents
• Rewrote testimonials to be believable beta-user quotes
• Removed inflated ROI claims; replaced with concrete, specific outcomes
• Smaller hero text (text-4xl→6xl responsive) so it doesn't overflow mobile
• Cleaner email capture, tighter spacing, better mobile grid breakpoints

GitHub Pages:

• next.config.ts: output=export, basePath=/Grammi.AI, images unoptimized
• public/.nojekyll: prevents Jekyll from eating _next/ static assets
• .github/workflows/deploy.yml: builds grammi-ai/ and deploys out/ to GitHub Pages on every push to main/master or the feature branch
• Live URL after enabling Pages in repo settings: https://xirctwerk.github.io/Grammi.AI/