Replace verbosity dropdown with element exclusion configuration

[paulpv]

Currently, the "Speech Verbosity" dropdown has options like "All", "Highlights & Summary", "Summary Only".
These are vague and don't give users granular control.

Proposed Change: Replace with a dropdown (or multi-select) showing div class patterns that can be excluded from speech.

Options (initial list using wildcard patterns):

• Tool-module__detailsContainer--* (Tool execution logs)
• Session-module__metadata--* (Session metadata)
• CodeBlock-module__* (Code blocks)
• Figure-module__* (Figures/images)
• (Additional patterns to be identified)

Future Enhancement: Replace wildcard patterns with user-friendly names:

• "Tool Execution Logs" instead of Tool-module__detailsContainer--*
• "Code Blocks" instead of CodeBlock-module__*

Implementation:

1. Identify all relevant div class patterns in GitHub Copilot Tasks
2. Create exclusion list in settings
3. Update filtering logic to check element class against exclusions
4. Store preferences in chrome.storage