Stateful flows (#1931)

* fix: ensure persisted state overrides class defaults

- Remove early return in Flow.__init__ to allow proper state initialization
- Add test_flow_default_override.py to verify state override behavior
- Fix issue where default values weren't being overridden by persisted state

Fixes the issue where persisted state values weren't properly overriding
class defaults when restarting a flow with a previously saved state ID.

Co-Authored-By: Joe Moura <joao@crewai.com>

* test: improve state restoration verification with has_set_count flag

Co-Authored-By: Joe Moura <joao@crewai.com>

* test: add has_set_count field to PoemState

Co-Authored-By: Joe Moura <joao@crewai.com>

* refactoring test

* fix: ensure persisted state overrides class defaults

- Remove early return in Flow.__init__ to allow proper state initialization
- Add test_flow_default_override.py to verify state override behavior
- Fix issue where default values weren't being overridden by persisted state

Fixes the issue where persisted state values weren't properly overriding
class defaults when restarting a flow with a previously saved state ID.

Co-Authored-By: Joe Moura <joao@crewai.com>

* test: improve state restoration verification with has_set_count flag

Co-Authored-By: Joe Moura <joao@crewai.com>

* test: add has_set_count field to PoemState

Co-Authored-By: Joe Moura <joao@crewai.com>

* refactoring test

* Fixing flow state

* fixing peristed stateful flows

* linter

* type fix

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Joe Moura <joao@crewai.com>

src/crewai/utilities/paths.py

@@ -7,7 +7,7 @@ import appdirs
 
 def db_storage_path() -> str:
     """Returns the path for SQLite database storage.
-    
+
     Returns:
         str: Full path to the SQLite database file
     """
@@ -16,7 +16,7 @@ def db_storage_path() -> str:
 
     data_dir = Path(appdirs.user_data_dir(app_name, app_author))
     data_dir.mkdir(parents=True, exist_ok=True)
-    return str(data_dir / "crewai_flows.db")
+    return str(data_dir)
 
 
 def get_project_directory_name():
@@ -28,4 +28,4 @@ def get_project_directory_name():
     else:
         cwd = Path.cwd()
         project_directory_name = cwd.name
-        return project_directory_name
+        return project_directory_name