Missena Bid Adapter: add GPP params to cookie sync URL

[ysfbsf]

Append gpp and gpp_sid macros to the usersync iframe URL so that GPP consent data is forwarded during cookie sync.

🔧 Type of changes

• new bid adapter
• bid adapter update
• new feature
• new analytics adapter
• new module
• module update
• bugfix
• documentation
• configuration
• dependency update
• tech debt (test coverage, refactorings, etc.)

✨ What's the context?

The Missena usersync iframe URL currently passes GDPR (gdpr, consent) and US Privacy (us_privacy) parameters but does not forward GPP consent data. The IAB's Global Privacy Platform has superseded US Privacy strings, and Prebid Server already resolves {{gpp}} and {{gpp_sid}} macros in usersync URLs.

🧠 Rationale behind the change

Adding gpp={{gpp}}&gpp_sid={{gpp_sid}} to the existing usersync URL ensures that GPP consent signals are forwarded to the Missena sync endpoint. This is a configuration-only change — no code is modified, only the missena.yaml bidder config file. Existing GDPR and US Privacy parameters are preserved for backward compatibility.

🔎 New Bid Adapter Checklist

N/A — this is a config update to an existing adapter.

🧪 Test plan

• Verified that the {{gpp}} and {{gpp_sid}} macros are supported by Prebid Server Java's usersync URL resolution
• Corresponding Prebid.js client-side change adds GPP support to getUserSyncs (PR pending on prebid/Prebid.js)
• Corresponding docs change adds gpp_sids declaration to dev-docs/bidders/missena.md (PR pending on prebid/prebid.github.io)

🏎 Quality check

• Are your changes following our code style guidelines?
• Are there any breaking changes in your code? — No
• Does your test coverage exceed 90%? — N/A, config-only change
• Are there any erroneous console logs, debuggers or leftover code in your changes? — No