Added postnitro.ai affiliate program

[iAmMuneeb]

Added PostNitro.ai to the affiliate program list

[vercel]

@iAmMuneeb is attempting to deploy a commit to the affitor Team on Vercel.

A member of the Team first needs to authorize it.

[sonpiaz]

Thanks for the contribution! A few fixes needed before merge:

1. Filename missing .yaml extension

• Current: programs/postnitro-ai
• Should be: programs/postnitro-ai.yaml

2. short_description is truncated and exceeds 100 char limit
Current value contains a literal newline and ends mid-sentence ("...no earning caps. \n\nFree to join, no e"). Schema requires maxLength: 100, single line.

Suggested fix:

short_description: "AI carousel maker for LinkedIn, Instagram, TikTok — 20% recurring lifetime"

3. commission.rate should be a string

commission:
  rate: "20%"   # not bare 20

Once these are fixed I'll merge. See schema/program.schema.json for full reference.