docs: update GMA iOS plugin to v3.1.0 with version compatibility table

[sunnywu]

Summary

The GMA iOS plugin documentation was last updated for v1.0.0 (October 2024). This PR brings it up to date with the v3.1.0 release (June 2026).

• Bumps documented version from 1.0.0 → 3.1.0
• Updates GMA SDK minimum requirement from v10.7.0 → v13.0.0
• Updates installation examples (Package.swift, Xcode, CocoaPods) to reference v3.1.0
• Adds a Version compatibility table showing which GMA Plugin version works with which GMA SDK and UID2 iOS SDK versions:

GMA Plugin Version	GMA SDK Version	UID2 SDK for iOS Version
3.1.0 (latest)	13.x	1.7.0 – 3.x
3.0.0 – 3.0.2	13.x	1.7.0 – 2.x
2.0.0 – 2.0.2	12.x	1.7.0 – 1.x
1.0.0 – 1.0.1	10.7.0 – 11.x	1.7.0 – 1.x
0.3.0 – 0.4.0	10.7.0 – 11.x	0.2.0 – 1.x

• Same changes applied to the Japanese translation

Test plan

• Verify rendered page at /docs/guides/mobile-plugin-gma-ios shows v3.1.0 and the compatibility table
• Verify Japanese translation renders correctly
• Confirm version numbers match latest release and Package.swift

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