[id774]

Summary

• replace minimal license-only source headers with complete product-style file headers
• document each file's responsibility, repository metadata, and requirements, with an initial v1.0 history for source, test, script, schema, and build files (plain configuration files carry no Version History)
• add usage or test information to entry points and test suites where it is part of the file's interface
• preserve all executable, API, configuration, build, and deployment behavior

Validation

• verified header coverage for every in-scope repository-authored file (131 files)
• verified generated files, committed migrations, JSON files, and documentation remain unchanged
• verified body semantics are unchanged outside headers/comments (comment-stripped comparison against the base branch)
• npm run format:check: pass
• npm run lint: pass
• npm run typecheck: pass
• npm test: pass
• npm run build: pass
• npm run openapi:lint: pass
• npm run prisma:validate: pass
• npm run synth: pass
• docker compose config: pass
• git diff --check: pass
• backend and frontend Docker image builds: not run locally (the build environment could not reach the npm registry from inside the container); covered by the CI containers job

Scope

Header/documentation-only maintenance across repository-authored source, test,
entry-point, build, deployment, and comment-capable configuration files.
No behavior, dependency, API, schema, package version, or release change is included.