v0.3.0

Current release after repository rename and core-pack cleanup.

Highlights:

• Canonical public repository: oneingan/design-context
• Default vendored path for consumer repos: docs/vendor/design-context/
• Core context pack and vendoring boundary documented in VENDORING.md
• Agent-readable design context framework for DDD, workflows, patterns, playbooks, and review checklists
• Lightweight validation includes ripgrep in the validation environment
• Prior repository history and previous release milestones remain visible (v0.1.0, v0.2.0)

Release commit: 3dc28d62fa328d0bee330779e8cb1bb66ccdac5c.