docs: record found experiments dogfood

[BrickerP]

What changed

• Record the live desktop and mobile dogfood evidence for Found Experiments.
• Separate archive display order from the independently verified portal journeys.
• Make the post-release stop condition the sole active Step 7 contract.

Why

The implementation is already live. These additions close Creative Builder Steps 6 and 7 with an evidence-bounded release record and prevent historical participant protocols from being mistaken for active work.

Impact

Documentation only. No Profile UI, runtime, publishing mechanism, or release cadence changes.

Validation

• Final documentation review: PASS
• Cached scope: exactly docs/creative/06-dogfood.md and docs/creative/07-next-loop.md
• git diff --cached --check: PASS before commit
• Local tests/build: not run; documentation-only change, per repository workflow