Schema Extension System for Modular ProjectBundle Extensions

[djm81]

Schema Extension System for Modular ProjectBundle Extensions

Why

Modules need a mechanism to extend ProjectBundle with custom fields without modifying core models, enabling marketplace-ready interoperability where external services (ADO, Jira, Linear) can persist metadata without core coupling. Without this, modules either duplicate schema logic or introduce tight coupling, blocking parallel development and ecosystem growth.

What Changes

• NEW: Add extensions field to Feature and ProjectBundle models with namespace-prefixed accessors/mutators
• NEW: Create src/specfact_cli/models/dynamic_extensions.py for Pydantic dynamic model creation
• MODIFY: Extend module manifest schema (module-package.yaml) with schema_extensions declaration
• MODIFY: Extend module lifecycle registration to load and validate schema extensions from manifests
• NEW: Add namespace enforcement (module-prefixed fields) with static analysis guards
• NEW: Add documentation for extending ProjectBundle and best practices

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OpenSpec Change Proposal: arch-07-schema-extension-system