[Swagger] Dedupe /auth/2fa/setup; add operationIds and machine-readable roles

[kingksjo]

Domain: API Docs / Metadata

Tier: 🟡 Medium

Description:
/api/auth/2fa/setup declared twice (~L1615 & L1700 — invalid duplicate key). Zero operationIds repo-wide. Role info is prose-only except one x-required-role (~L2693).

Dependencies: None.

Acceptance Criteria:

• Duplicate removed (keep richer block); unique operationIds everywhere (<tag>_<method>_<path> style).
• x-required-role applied per route from actual requireRole args.

Testing Requirements:

• Script/grep proves zero duplicate keys + full operationId coverage.

PR Checklist:

• Branch: docs/p3-09-operation-metadata

[ojuotimi932]

@ojuotimi932 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi Maintainer Can I resolve this kindly assign

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ojuotimi932 to this issue.

[udokaamoni]

@udokaamoni has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

hi maintainer please assign me to this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @udokaamoni to this issue.