[BUG] Project creators are not added as project members

[martian56]

Summary
A workspace member can create a project, but project creation does not add that user as a project member or admin.

Where I saw it

• api/internal/service/project.go, Create only inserts the projects row.
• api/internal/store/project.go has AddProjectMember, but ProjectService.Create does not call it.
• requireProjectAdmin allows workspace admins or project admins, so a regular workspace member who creates a project may not be able to manage that project afterwards.

Why this is a problem
The project creator should be able to configure the project they just created. Without a project member row, a non-admin workspace member can create a project and then be blocked from project settings, member management, or other admin-only project actions.

Suggested fix
Create the project and creator membership in one transaction. The creator should probably be project owner or project admin, depending on the intended role model.

Acceptance criteria

• Creating a project also creates a project_members row for the creator.
• The creator can immediately open and save project settings.
• The creator can invite or manage project members if their assigned role allows it.
• API tests cover project creation by a regular workspace member.

Checked on
main at f8e5946