docs: add QuietHarness usage receipt intake

[runesleo]

Why

QuietHarness has measurable interest, but the repository still lacks attributable evidence that a non-author installed it, reached first success, or reused it later. This PR adds the smallest measurement surface instead of another feature.

What changed

• add a bilingual, privacy-safe GitHub usage-receipt issue form
• link completed or blocked first-success users to that receipt from README.md
• mirror the CTA in README.en.md

The receipt captures client, version, install scope, elapsed time, private-support time, directly observed first-success behaviors, friction, and 7-day reuse. It explicitly asks users not to include private code, repository names, absolute paths, credentials, or account details.

Validation

• ./scripts/verify.sh → INVENTORY_SMOKE_OK, INSTALL_SMOKE_OK, FIRST_SUCCESS_SMOKE_OK, VERIFY_OK template_bytes=2318
• git diff --check
• exact three-file whitelist
• forbidden-content / credential-pattern scan
• YAML parse + GitHub common issue-form contract checks
• Chinese / English CTA mirror check

No product behavior, installer behavior, release, or deployment is changed by this PR.