Apply packaged-resource boundaries to automatic discovery #437

🤖 Generated by the Agentic Engineer

Problem

The package validator checks regular contained files for explicit components but automatic discovery can accept linked skill, agent and MCP resources. A discovered skill link can also bypass the regular-file provenance census. The same package boundary must apply to both discovery modes.

Proposed direction

Require automatically discovered component roots and resources to be regular contained package content before validation, catalogue counting and provenance observation. Do not follow linked resources as packaged evidence.

Acceptance criteria

• Linked skill files/directories, agents and MCP configurations are refused in default discovery.
• Explicit component protections remain enforced.
• Regular automatic and explicit resources still validate.
• Meaningful positive and negative production-validator cases run in CI.

Size: S. Part of #38.