Add confirmation dialog before deleting rules

[komallsingh]

Summary

Adds a confirmation dialog before deleting rules to prevent accidental deletions.

Changes

• Added rulePendingDeletion state to track pending deletions
• Added Compose AlertDialog confirmation flow
• Applied confirmation to swipe-to-delete actions
• Applied confirmation to delete action from the rule details dialog
• Deletion now only occurs after explicit user confirmation

Testing

Manual Verification

Due to AI Engine availability issues, rule creation could not be tested end-to-end on available emulators.

Environment tested:

• Pixel 9 Pro emulator
• Additional Android emulators

Observed behavior:

• App reports: "AI model unavailable — please set up on-device AI first"
• No rules can be created through the Chat flow because parseCommandUseCase() fails before rule creation

Code inspection confirms:

• Existing deletion behavior directly called viewModel.deleteRule(rule)
• New implementation replaces immediate deletion with a confirmation dialog
• Actual deletion now occurs only after user presses "Delete"

Expected Behavior

• Tapping delete shows a confirmation dialog
• Dialog displays the rule name
• Dialog warns that the action cannot be undone
• Cancel keeps the rule
• Delete removes the rule

NOTES

I would also mention:

I was unable to fully verify via UI because the AI engine is unavailable on available emulator devices (including Pixel 9 Pro emulator), preventing rule creation through the Chat workflow. The change is isolated to the UI layer and does not modify repository or ViewModel deletion logic.