0.1.5 — performance fix

Performance fix release for long-note reading.

Changes:

• Remove the global browser text rendering override from theme.css.
• Keep the injected snippet synchronized with theme.css.
• Bump manifest.json and README release references to 0.1.5.

Validation:

• Verified theme.css matches inject-kami-snippet.js.
• Verified the old text rendering override is absent.
• Verified manifest.json and data-theme.json parse correctly.
• Verified inject-kami-snippet.js parses with Node.