data: add PulseADT startup credit

[Himtome1]

What changed

Adds PulseADT and one qualifying offer from its Startup Credit Program. The single Offer models the API Builder track: the $100 minimum spend within 90 days, $250 credit valid for 12 months, subsequent ongoing 30% discount, published extras, full eligibility, and public application route.

Closes #1235

Sources

• https://getpulseadt.com/for-startups

Certification

• I changed only allowed repository content and did not mix Entity YAML with other paths.
• Public sources substantiate every submitted factual value; any Sourcey-written prose is a neutral summary, not a fabricated vendor quote.
• I did not author verification, provenance, freshness, or signature claims.
• My commits include a Signed-off-by line.

Validation

The pinned local Sourcey catalog verifier passes for exactly 1 Entity, 1 Program, and 1 Offer.