Update website with new branding and French version

- Add French version (fr.html) with localized content
- Update logos to new Atomaste branding (light grey logo, favicon)
- Update slogans to use team voice and general language
- Add deployment scripts for Dalidou dev server
- Remove old unused logo files
- Add .gitignore for IDE and sync folders

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,14 @@
+# Syncthing
+.stfolder/
+.stignore
+
+# IDE
+.vscode/
+.idea/
+
+# Claude Code
+.claude/
+
+# Local/temp files
+*.tmp
+*.bak