ObjectScriptEntity - Inline script definitions for single-file games

[Natuworkguy]

Currently, entity scripts must be defined in separate files and loaded via file paths. This prevents users from writing complete games in a single Python file.

Proposed Solution:

Add a new ObjectScriptEntity subclass that accepts a script class directly instead of a file path. The class should implement the following:

• Accept a scriptobj argument (type: ScriptProtocolType) instead of scriptfile
• Set scriptfile to None internally
• Check which lifecycle methods exist on the script class at creation time and skip calling missing methods

Implementation Details:

1. Add ScriptProtocol and ScriptProtocolType to engine/core/types.py:

   • ScriptProtocol defines the structural contract (init, update, event methods)
   • ScriptProtocolType = type[ScriptProtocol] to accept the class itself
   • Delete ScriptProtocol after alias creation to keep public API clean

2. Create entity/core/ose.py with ObjectScriptEntity:

   • Subclass Entity
   • Override __new__ to instantiate Entity, set scriptfile=None, and store scriptobj

3. Update documentation with usage examples and clarify that self in script methods is the entity instance, not the script object

Acceptance Criteria:

• Users can write a complete game in one .py file without external script files
• Type checkers recognize script objects via ScriptProtocolType
• Documentation clarifies the self → entity mapping