UX: Make policy parameter changes more intuitive - remove need to click 'Add parameter'

Problem

When modifying policy parameters, users must:

1. Change the value (e.g., toggle a boolean switch)
2. Click "Add parameter" button
3. Review and create policy

Step 2 is easy to miss, especially for boolean switches where toggling feels like the action itself. Users expect the change to be captured immediately when they modify a value.

This was discovered when a user reported that their boolean policy change wasn't saving (#602) - they had toggled the switch but didn't realize they needed to click "Add parameter".

Proposed Solutions

Option A: Auto-add on change (Recommended)

• Automatically add the parameter to the policy when the value changes
• Remove the "Add parameter" button entirely
• Show a visual indicator that the parameter has been added (e.g., checkmark, highlight)

Option B: Make "Add parameter" more prominent

• Highlight the button after a value change
• Add tooltip: "Click to apply this change"
• Disable "Review my policy" until changes are added

Option C: Warn before proceeding

• If user has unsaved parameter changes, show a warning when clicking "Review my policy"
• "You have unapplied changes. Add them before continuing?"

Impact

This affects all parameter types but is especially confusing for boolean switches where the toggle action feels complete on its own.

Start by reproducing the policy parameter editing flow, especially changing a boolean value and proceeding to review. Compare the proposed auto-add, prominent-button, and warning approaches with the existing behavior. Done means parameter changes are reliably captured before policy review and the chosen interaction makes that state clear.