chore: add copyright headers to web config and demo modules

[karagozemin]

Add a per-file copyright header so ownership is visible at the file level (consistent with the root LICENSE).

Mechanical change — prepend this exact line as the first line of each file, nothing else:

// Copyright (c) 2026 Sub Rosa contributors

Add it to the following files:

• apps/web/src/config/routing.ts
• apps/web/src/config/useCases.ts
• apps/web/src/demo/demo-trace.checksum.ts
• apps/web/src/demo/demo-trace.generated.ts
• apps/web/src/demo/trace-health-check.ts
• apps/web/src/demo/trace.ts

[Adeyemi-cmd]

Can i please work on this

[grantfox-oss]

🦊 GrantFox — @Adeyemi-cmd has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #212)
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