[FEAT]: Migrate frontend to fireform-core/fireform-frontend and remove legacy code

[marcvergees]

📝 Description

Now that the new frontend repository (fireform-core/fireform-frontend) has been established, migrate all frontend code and assets from this repository, eliminate residual frontend files/configurations, and update documentation to reflect the backend-only status of FireForm.

💡 Rationale

Migrating the frontend code to its own repository helps to clearly separate backend and frontend concerns, reduces clutter in the backend repository, simplifies deployment, and makes future maintenance easier.

🛠️ Proposed Solution

• Move all necessary frontend-related code/assets to fireform-core/fireform-frontend (if not already migrated).
• Remove all obsolete frontend code, assets, and dependencies from this repository.
• Clean up package.json, Dockerfiles, and related configs to exclude frontend content.
• Update documentation to explain the new repo split and backend-only scope here.
• Check for and eliminate frontend scripts/references from CI/CD workflows.

✅ Acceptance Criteria

• All frontend resources fully migrated and validated in the new repo.
• This repo is left with only backend/server code.
• Documentation is updated accordingly.

📌 Additional Context

Splitting the frontend and backend codebases helps with maintainability, on-boarding, and deployment pipelines. Double-check for any hard-coded paths or documentation references to the old frontend.