[P1] Publish design-partner onboarding and feedback cadence

[tcconnally]

Goal

Make first-user onboarding repeatable for 5–10 high-fit design partners, beginning with CTO/founder teams using real LLM or agent workloads.

Deliverables

• One-page onboarding guide: signup, verify email, Cloud dashboard, Plutus Google sign-in, API-key creation, first usage event.
• Day 0 / Day 3 / Day 7 outreach cadence.
• Feedback template: one friction point, one useful metric, willingness-to-pay signal.
• Clear statement: Free covers teams of 10 or fewer; no card and no automatic charge; optional donation only after verified savings.

Acceptance criteria

• A design partner can reach the first metered usage event without live assistance.
• Outreach never advertises a self-serve paid checkout while it is disabled.
• The guide links to the exact public URLs and does not contain credentials.