v0.2.1 - Disabled Control Boundary

This preview adds an explicit prompt boundary for disabled and read-only page controls, plus a regression test for the example host allowlist.

• The risk module directs agents to use visible UI prerequisites and stop if the control remains unavailable.
• The local controller rejects an evaluate action before its executor callback.
• GitHub Actions passed on commit bfb9c8258fc60c9f436e4337a50f236ded87b57a: 42 unit/contract tests, builder and skill parity, browser workflows and local recovery demos.

This is not a fix for Browser Use or another vendor agent. No LLM or live vendor runtime was tested. The prompt is guidance; the example allowlist only governs actions routed through that controller. See the scoped evidence in docs/verification.md and the motivating Browser Use report.