f119ec30ca
Tranche 1 of LST-65 (ProjectManagement module migration). Decouples the TimeTracking module from the core-business entities before they move, with no entity relocation yet — keeps the diff minimal and the risk isolated. - New read contracts in Shared/Domain/Contract (minimal surface, aligned on the entities' real nullable signatures): ProjectInterface (id/code/name), TaskInterface (id/number/title), TaskTagInterface (id/label/color), ClientInterface (id/name). - Project/Task/TaskTag/Client implement their contract (entities stay in src/Entity for now). Project.client typed as ClientInterface. - TimeEntry (TimeTracking) now references ProjectInterface/TaskInterface/ TaskTagInterface instead of the concrete entities; repository + DQL untouched in behaviour. - resolve_target_entities maps the 4 contracts to the legacy entities (will be repointed to the module in tranche 2). - Adds the migration plan doc. 159 tests green, mapping valid, cs-fixer clean.