chore: optimize PNG images and add .gitattributes

- Optimize all documentation images with optipng -o7
  • 01-dashboard.png: 497KB → 372KB (25% reduction)
  • 02-storage.png: 408KB → 307KB (25% reduction)
  • 03-backups.png: 343KB → 261KB (24% reduction)
  • 04-alerts.png: 152KB → 118KB (22% reduction)
  • 05-alert-history.png: 324KB → 245KB (24% reduction)
  • 06-settings.png: 189KB → 146KB (23% reduction)
  • 08-mobile.png: 116KB → 85KB (27% reduction)
  Total savings: 2.0MB → 1.5MB (500KB saved, 25% reduction)

- Add .gitattributes file for proper binary file handling
  • Mark binary files (images, fonts, etc.) to skip diff
  • Mark lockfiles to skip diff generation
  • Enforce LF line endings for text files

.gitattributes

@@ -0,0 +1,46 @@
+# Binary files - don't attempt to diff
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.svg binary
+*.webp binary
+*.woff binary
+*.woff2 binary
+*.ttf binary
+*.eot binary
+*.otf binary
+*.pdf binary
+
+# Lockfiles - don't generate diffs
+package-lock.json -diff
+pnpm-lock.yaml -diff
+go.sum -diff
+
+# Generated files
+*.min.js -diff
+*.min.css -diff
+
+# Shell scripts - ensure LF line endings
+*.sh text eol=lf
+*.bash text eol=lf
+
+# Go files - ensure LF line endings
+*.go text eol=lf
+go.mod text eol=lf
+go.sum text eol=lf
+
+# Frontend files - ensure LF line endings
+*.js text eol=lf
+*.jsx text eol=lf
+*.ts text eol=lf
+*.tsx text eol=lf
+*.json text eol=lf
+*.md text eol=lf
+*.yml text eol=lf
+*.yaml text eol=lf
+
+# Dockerfile - ensure LF line endings
+Dockerfile text eol=lf
+*.dockerfile text eol=lf