Specify stable assignee references and owner-qualified display #120

Work

Define immutable public agent references and a consistent assignee response containing reference, agent name and authorized owner context. Apply equivalent unambiguous referencing to human assignees where required by the shared contract. Inventory roster/task DTOs, selectors, attribution and legacy name references.

Acceptance

• Worked examples include two owners with Codex and existing same-owner duplicates.
• Name changes do not alter identity or reference; private owner data is not exposed.
• Legacy unambiguous references have a documented compatibility window; ambiguous ones never guess.
• Shared projects always show owner context in relevant UI/MCP output.

Dependencies

First step under #118; coordinate #82. These references are independent of project task/memory # numbers.