0.1.8 — bold emphasis settings

What's changed

• Added a Style Settings control for bold emphasis strength (500, 600, 700) so users can calibrate bold readability across fonts and platforms without CSS snippets.
• Kept the default 500 bold weight to preserve Kami Reader's restrained long-form texture.
• Synced the theme-mode schema, snippet-mode schema, generated injector, manifest version, and release docs.

Verification

• git diff --cached --check
• Parsed data-theme.json and manifest.json
• Verified bold-weight select defaults/options are string values
• Verified inject-kami-snippet.js decodes exactly to theme.css