chore: renew Verify OpenSource sponsorship exemption before 2027-09-30

[samtrion]

User Story

As a Pulse maintainer, I want the Verify OpenSource sponsorship exemption renewed before it expires, so that builds and CI keep passing after 2027-09.

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Problem

Verify v33 and later check the Open Source Maintenance Fee at build time (SponsorCheck, owner id Verify). A build that references a Verify package fails with SC021 if it has no declaration. #728 added the OpenSource exemption to every test project that references Verify.TUnit:

• tests/NetEvolve.Pulse.SourceGeneration.Tests.Unit/NetEvolve.Pulse.SourceGeneration.Tests.Unit.csproj
• tests/NetEvolve.Pulse.Tests.Integration/NetEvolve.Pulse.Tests.Integration.csproj

<Verify_SponsorshipExemption>OpenSource</Verify_SponsorshipExemption>
<Verify_SponsorshipExemptionUntil>2027-09</Verify_SponsorshipExemptionUntil>

The exemption is time-bounded. The end month can be at most 12 months after the build date. Once 2027-09 has passed, every build that references Verify fails (SC047, exemption expired) until the claim is renewed.

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Specification

From the Verify maintenance-fee documentation:

All three exemptions are time-bounded, so an end month is required: at most 12 months ahead of the build date for SmallRevenue and OpenSource [...] Once the month has passed, the build fails until the claim is renewed.

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Requirements

• In September 2027, confirm that Pulse still qualifies for the OpenSource exemption: it is an open source project that does not generate revenue.
• If it still qualifies, set Verify_SponsorshipExemptionUntil to the latest allowed month (12 months ahead, e.g. 2028-09) in every project that references a Verify package, and update the renewal date in the XML comment next to it.
• If it no longer qualifies, switch to one of the other license modes described in the maintenance-fee documentation.
• Check whether any new projects reference Verify packages, and add the declaration there too.

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Acceptance Criteria

• The exemption end month is renewed before 2027-09 ends, in every project that references a Verify package.
• dotnet build Pulse.slnx -c Release passes with 0 warnings and 0 errors, and SC031 is logged instead of SC021/SC047.
• CI is green.
• A follow-up issue for the next renewal is created.