Release builds hash inline <style> blocks from index.html into the CSP.
With a hash present, style-src 'unsafe-inline' is ignored, so CodeMirror's
runtime-injected styles were blocked and the editor rendered blank (bare
line numbers, no text). Dev builds don't rewrite the CSP, so it only
showed in v0.1.3 release bundles.
Claude-Session: https://claude.ai/code/session_01B65qLEKnkeYTGdbwhLpjCu
