0.1.3 — nested list polish

Polish release for nested lists and Reading View consistency.

Changes:

• Align nested list typography and spacing between Reading View and Live Preview.
• Prevent external-link icons from overlapping link text in Reading View.
• Keep completed parent tasks from striking through nested child content.
• Add a screenshot and demo note for the completed-task nesting case.

Validation:

• Verified theme.css matches inject-kami-snippet.js.
• Verified manifest.json and data-theme.json parse correctly.
• Verified the new screenshot renders the fixed checklist behavior.