Add dynamic theme authoring workflow

[anhao]

What changed

• teach codedrobe-theme to capture live home and conversation DOM snapshots before writing detailed CSS
• add complete neutral Codex and WorkBuddy starter CSS under assets/theme-starter/
• add the complete Doll Sister / 玩偶姐姐 multi-app source theme and generated artwork
• document snapshot interpretation, selector choice, active-theme handling, privacy, packaging, and visual iteration
• update adapter-development guidance to use the Core snapshot
• validate bundled theme sources in CI

Why

Templates should accelerate design without becoming permanent DOM contracts. The Skill now combines reusable full CSS sources with current CDP evidence, then probes and verifies theme-specific dependencies.

Validation

• official npx skills discovery and selective installation
• Skill Creator validation for both Skills
• starter and Doll Sister source packages built with local Core and published @codedrobe/core
• Doll Sister passed real WorkBuddy probe and verify with no missing nodes or horizontal overflow

Dependency

Keep this PR in draft until @codedrobe/core 0.3.0 is published with codedrobe dom snapshot.