feat(quality): Quality score badge on every artifact (inject-quality-badge.py)

[ramsani]

feat(quality): Quality Score Badge on Every Generated Artifact

What

Implements Issue #14 — Quality Score Badge on every generated artifact.

New file: scripts/inject-quality-badge.py

Injects a quality score badge into an HTML artifact's body. Badge design:

• Score pill (e.g., 92/100 ✓) with color-coded tier
• Tier colors: green (90+), blue (75-89), yellow (60-74), red (<60)
• Shows checks passed count (e.g., 11/13 checks passed)
• Accessible: aria-label, WCAG AA color contrast, dark mode compatible
• CSS injected inline so it works as standalone HTML without external styles

Modified: scripts/deliver-artifact.py

Added --badge flag that calls inject-quality-badge.py after artifact approval.

New test: tests/test_quality_badge.py

• test_badge_90(): Score 90+ shows green .quality-passed badge
• test_badge_78(): Score 75-89 shows blue .quality-ok badge
• test_badge_idempotent(): Badge not injected twice on repeated calls

Why

The deliver-artifact.py script computes a quality score (0-100) but the score was invisible to stakeholders receiving an artifact. The badge:

1. Trust signal: User sees at a glance the artifact passed the quality gate
2. Accountability: Contributors see how their patterns perform
3. Comparability: Multiple artifacts compared by score without running audit

Acceptance Criteria (from #14)

• Every artifact passed by deliver-artifact.py --badge renders a quality badge in its HTML header
• Badge shows score (0-100), pass/fail status, and check count
• Badge color follows score tiers (green 90+, blue 75-89, yellow 60-74, red <60)
• Badge is accessible: has aria-label, sufficient color contrast
• Badge renders correctly in both light and dark mode
• audit-artifact.py --json output unchanged (backward compatible)
• Badge injection is idempotent (repeated calls don't add multiple badges)
• Tests validate all three scenarios

Testing

# Test badge injection
python scripts/inject-quality-badge.py --help
python scripts/inject-quality-badge.py /tmp/test.html --score 92 --checks-passed 11 --checks-total 13

# Test deliver-artifact integration
python scripts/deliver-artifact.py --help | grep badge

# Run tests
python tests/test_quality_badge.py

# Verify badge in artifact
grep 'quality-badge' /tmp/test.html
# Expected: quality-badge-header, quality-badge quality-passed

Closes #14