data: add Influship Startup Program

[matanita44-sudo]

What changed

Adds one new vendor record for Influship and its public Startup Program. The offer records the vendor’s project-sized API credit grant, technical onboarding, dedicated support, and early API access without inventing an unpublished monetary amount.

Sources

https://www.influship.com/startups

Certification

• I changed only allowed repository content and did not mix vendor 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.

Closes #681