Onboard Getting Started Step 7 lists wrong credibility threshold (75%) — actual is 80%

[aviu16]

Description

The Getting Started onboard page, Step 7 (Contribute), says the eligibility credibility threshold is 75%. The actual threshold in the validator code is 80% (MIN_CREDIBILITY = 0.80 in gittensor/constants.py). This is wrong enough that a new miner reading the Step 7 summary will hit the gate with 76–79% credibility and wonder why they're still listed as ineligible.

This is different from #147 (which covers the About and Scoring tabs) — this one is on the Getting Started tab specifically, in the Step 7 content block.

Also different from #151, which is about the OSS Eligible badge tooltip on the contribution leaderboard. That one says 90%. So there are now three different credibility numbers surfaced in the UI: 75% (Getting Started Step 7), 80% (actual), and 90% (badge tooltip).

Steps to Reproduce

1. Open https://gittensor.io/onboard?tab=getting-started
2. Click the 7 Contribute circle in the stepper (or scroll to Step 7 content)
3. Under "Step 7: Contribute" the text reads:

   Eligibility requires 5 merged PRs with token score ≥ 5, 75% credibility, and a 180-day-old GitHub account

Expected Behavior

Show 80% to match the validator:

Eligibility requires 5 merged PRs with token score ≥ 5, 80% credibility, and a 180-day-old GitHub account

Actual Behavior

Says 75%, which no gate in the scoring code actually uses.