fix(frontend): replace 'CREs' with 'Requirements' in user-facing text

[rashmivemuri]

Fixes #453

Problem

New visitors to OpenCRE don't know what a "CRE" is, making the UI
confusing for first-time users.

Changes

Updated user-facing display strings in application/frontend/src/const.ts:

• "is part of CREs" → "is part of Requirements"
• "is linked from CREs" → "is linked from Requirements"
• "contains CREs" → "contains Requirements"
• "is related to CREs" → "is related to Requirements"

Note: bundle.js is auto-generated and will update automatically on rebuild.
Please let me know if changes to docs/implementation.md or any other
files are also required and I'll update the PR.

[northdpole]

Closing as stale and conflicting.

This was a 4-line frontend string swap (CREs → Requirements in const.ts, #453). The branch has been DIRTY since March with no viable rebase path. We still want friendlier wording, but it should land in a fresh PR against current UI copy.

Thank you @rashmivemuri.