[Bug] Writer of a cross-org shared artifact can publish from one account but gets "not found" from another #109194

Related to #107318, with one difference: whether a writer can publish depends on which account Claude Code is logged in with, not on the share settings.

Setup: an artifact owned by account X, shared with edit access to account A (Team org) and account B (personal). macOS, Claude Code 2.1.322.

• Logged in as A: no built-in Artifact tool. claude-artifacts get_artifact / read_artifact return not found for the short id, the URL and the UUID. claude -p --strict-mcp-config and 2.1.308 also had no Artifact tool.
• After /login as B in the same session: Artifact came back, read says "shared with you from another organization (writer)", and publish with url worked.

Expected: A can publish too, since it has the same edit access.