feat(devcontainer): enhance devcontainer setup with SSH and utilities

feat(devcontainer): enhance setup with SSH and environment scripts

refactor(frontend): reorganize layout/shared components and unify border token

feat(frontend): add core layout components and update UI structure

chore(tooling): expand gitignore to exclude scripts and temporary files

refactor(backend): simplify job status history repr formatting

chore(docs, tooling): remove gitmessage template and correct README layout

chore(tooling, ci, docs): update pre-commit hooks and add commitlint workflow

chore(style, backend): introduce pre-commit pipeline and apply project-wide formatting cleanup

feat(api, job-tags): introduce job–tag linking domain with full CRUD and validation

feat(api, job-status-history): add job status history domain with full CRUD and validation

feat(api, job-file-attachments): introduce job file attachment domain with full CRUD and lifecycle operations

refactor(api, job-events, models, schemas, services, tests): introduce job event domain with full CRUD and user‑scoped architecture

refactor(api, models, schemas, services, repositories, tests): introduce tag domain with full CRUD and unified architecture

refactor(api, models, repositories, services, schemas, tests): introduce job & interview domains with unified patterns and full test coverage