feat: propagate constructor kwargs to initial state callbacks

[fgmacedo]

Summary

• Forward **kwargs from StateChart.__init__() through the engine's __initial__ event, making them available to on_enter_<state>, invoke handlers, and all initial-entry callbacks via dependency injection
• Self-contained machines can now receive context at creation time:

class Greeter(StateChart):
    idle = State(initial=True)
    done = State(final=True)
    idle.to(done)

    def on_enter_idle(self, name=None, **kwargs):
        self.greeting = f"Hello, {name}!"

sm = Greeter(name="Alice")
sm.greeting  # "Hello, Alice!"

• Especially useful for invoke handlers on initial states:

class AppLoader(StateChart):
    loading = State(initial=True)
    ready = State(final=True)
    done_invoke_loading = loading.to(ready)

    def on_invoke_loading(self, config_path=None, **kwargs):
        return json.loads(Path(config_path).read_text())

sm = AppLoader(config_path="/etc/app.json")

Changes

• StateChart.__init__() passes **kwargs to engine.start()
• BaseEngine.start(), SyncEngine.start()/activate_initial_state(), and AsyncEngine.activate_initial_state() accept and forward **kwargs
• kwargs are stored in TriggerData.kwargs for the __initial__ event, flowing naturally through EventData.extended_kwargs to all callbacks
• Updated docs/invoke.md and docs/releases/3.0.0.md

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (f1cbfbb) to head (cb5ab3f).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files           33        33           
  Lines         4044      4044           
  Branches       635       635           
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  Hits          4044      4044           

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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