Observed 70% false-positive rate on renderer/shader codebases (hyperframes):
GLSL, CSS-in-JS, inline HTML/SVG, ffmpeg filter-strings, hardcoded
User-Agent strings all matched base64-like entropy thresholds. This
commit adds two suppression layers before classification.
Layer A — file-extension skip: .glsl/.frag/.vert/.shader/.wgsl (shaders),
.css/.scss/.sass/.less (stylesheets), .svg (markup), .min.js/.min.css
(minified bundles). Tracked via new calibration.files_skipped_by_extension
field on scanner envelope for synthesizer stats.
Layer B — seven new line-level suppression rules in isFalsePositive()
(rules 11-17): GLSL/WGSL keywords, CSS-in-JS (styled/emotion/@keyframes),
inline HTML/SVG markup, ffmpeg filter-graph syntax, browser User-Agent,
SQL DDL/DML, error-message templates with embedded HTML.
Existing entropy.test.mjs: 9/9 still green — known bad base64 payload in
telemetry.mjs fixture still detected. Policy-driven thresholds wired in
Commit 3.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
