Release Core 0.3.0 with DOM snapshots

[anhao]

What changed

• add privacy-preserving codedrobe dom snapshot CLI and snapshotDom() API
• return semantic selector candidates, match counts, layout, computed styles, adapter landmarks, and active-theme state
• exclude text, input values, accessible names, query/hash data, links, and media sources
• add multi-image theme packages, Codex transactional host settings, renderer profiles, and high-level apply/restore orchestration
• add the complete Codex and WorkBuddy Doll Sister source example
• prepare @codedrobe/core 0.3.0

Why

Theme-authoring agents need current renderer evidence instead of relying on permanently hardcoded application selectors. The snapshot remains read-only and bounded while giving agents enough structural and style information to generate app-specific CSS.

Validation

• npm test (46 tests)
• npm run pack:check
• real WorkBuddy 5.2.6 DOM snapshot: 317 visible nodes, no truncation
• real Doll Sister WorkBuddy probe and verify, including screenshot, named images, and overflow check

Release order

Merge this PR and publish GitHub release v0.3.0 before merging the dependent CodeDrobe/skills PR.