Unify release layout and branding

[itamaker]

Summary

• align go-chrome-ai release artifact naming and checksums with the other managed repos
• add unified social preview and logo assets plus README layout updates
• extend installer compatibility so existing v1.0.3 downloads still work until the new release lands

Verification

• go test ./...
• go build ./cmd/go-chrome-ai
• goreleaser check
• goreleaser release --snapshot --clean --skip=publish
• install.sh against v1.0.3 with fallback to legacy asset names
• export-repos.sh now exports go-chrome-ai as well