fix: e2e test locator change update

[Ragini-Microsoft]

Purpose

This pull request makes minor adjustments to the HomePage test page object to improve robustness and clarity in locator definitions and docstrings. The changes focus on making element locators more flexible and updating documentation for accuracy.

Locator improvements:

• Changed the AGENT locator to use a more flexible XPath that matches any element containing the text "PlanningAgent", rather than requiring an exact match.
• Updated the ANALYZING_BRIEF_TEXT locator to match the new text "Processing your request" instead of "Analyzing creative brief..".

Documentation updates:

• Simplified and clarified the docstring for validate_planning_agent_response_quality, removing references to the PlanningAgent label and focusing on content validation. [1] [2]
• Updated the exception description in the docstring to reflect that it now asserts only on missing baseline brief content, not the PlanningAgent label.

Test logic adjustment:

• Removed the assertion checking for the visibility of the PlanningAgent label, focusing validation solely on the content of the response.

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

What to Check

Verify that the following are valid

• ...

Other Information