Use { userToHost } and { hostToUser } contexts.

[vic]

Instead of previous: { fromUser, toHost } and { fromHost, toUser }.

The reason is detailed at #47.

Closes #47.

[Copilot]

Pull Request Overview

This PR refactors the context structure in the aspect system to improve API clarity. Instead of using flat fromUser/toHost and fromHost/toUser parameters, the new API uses nested structures userToHost (with .user and .host fields) and hostToUser (with .host and .user fields), making the direction of contribution more explicit.

Key Changes:

• Replaced { fromUser, toHost } parameter pattern with { userToHost, ... } where userToHost contains .user and .host fields
• Replaced { fromHost, toUser } parameter pattern with { hostToUser, ... } where hostToUser contains .host and .user fields
• Updated all aspect definitions and examples to use the new nested context structure
• Added test coverage for the new userToHost context pattern
• Improved code maintainability by using inherit destructuring consistently

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
templates/default/modules/_profile/users/fido/common-host-env.nix	Updated user-to-host contribution to use nested userToHost.user and userToHost.host structure
templates/default/modules/_profile/profiles/single-user-is-admin.nix	Refactored to use userToHost context with destructuring, added __functor for proper context propagation, simplified includes logic
templates/default/modules/_profile/hosts/bones/common-user-env.nix	Updated host-to-user contribution to use nested hostToUser.host and hostToUser.user structure
templates/default/modules/_example/aspects.nix	Updated example aspects to demonstrate the new userToHost and hostToUser API patterns
modules/aspects/provides/user-shell.nix	Refactored userToHostContext to destructure userToHost and access nested user field
modules/aspects/provides/primary-user.nix	Updated to destructure userToHost into host and user for cleaner code
modules/aspects/provides/define-user.nix	Refactored to use destructured userToHost context with explicit inherit declaration
modules/aspects/dependencies.nix	Core implementation of the new nested context structures in hostIncludesFromUsers and userIncludesFromHost functions
checkmate/tests/aspect-functor.nix	Added test case for the new userToHost context pattern to ensure proper functor behavior

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.