Fix language bar hover details

[2js56]

Fixes #8

Summary

• Replaces the language color buttons with non-clickable language bar segments.
• Shows the language name and percentage on hover/focus.
• Keeps logout behavior only on the logout button instead of each language bar.

Validation

• tsc --noEmit -p tsconfig.web.json --composite false
• tsc --noEmit -p tsconfig.node.json --composite false
• npm run build
• git diff --check