Add appeal workflow for blocked listings

[Copilot]

Blocked listings now display moderation context and provide users a path to appeal administrative actions.

Domain Changes

ItemListing entity:

• Added blockReason and blockDescription optional fields
• Added block() application service to set block metadata
• Extended repository interface with getByListingId() for appeal request lookups

GraphQL API:

type ItemListing {
  blockReason: String
  blockDescription: String
  # ... existing fields
}

input BlockListingInput {
  id: ObjectID!
  blockReason: String!
  blockDescription: String!
}

mutation blockListing(input: BlockListingInput!): ItemListingMutationResult!
query getListingAppealRequestByListingId(listingId: ObjectID!): ListingAppealRequest

UI Components

BlockInformationModal:

• Renders admin-provided block reason and description
• Actions: Edit Listing, Appeal Block, Cancel
• Disables appeal button if request already submitted

AppealConfirmationModal:

• Confirms user intent before submitting appeal
• Warns to update listing before appealing

ViewListing updates:

• Red banner displays when listing.state === 'Blocked'
• "View Details" button triggers block information modal
• Banner updates to "Your appeal is awaiting approval" post-submission
• Success alert shows after appeal submission

Security Notes

Placeholder TODOs added for:

• Role-based authorization on blockListing mutation (admin-only)
• Authentication checks on getListingAppealRequestByListingId query
• Blocker ID tracking (currently uses placeholder value)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Listing - Appeal Blocked Listing</issue_title>
<issue_description>When a listing is marked as Blocked, the listing detail page should display a red banner at the top stating:
“This listing is blocked.”

When hitting "view details", a Block Information modal appears showing:

• Reason (e.g., Profanity)
• Description (admin explanation of the violation)

The modal includes the following actions:

• Edit Listing – redirects to the edit form
• Appeal Block – opens a confirmation modal
• Cancel – closes the modal

The Appeal Confirmation modal displays a message and two buttons (shown in the picture below)

After the user submits an appeal, the banner updates to:
“This listing is blocked. Your appeal is awaiting approval.”

and a success message appears below:
“Appeal requested successfully.”

Functional Requirements:

• Show the block info modal automatically when listing.status === 'Blocked'
• Populate reason and description from backend response
• Edit button navigates to the listing edit screen
• Appeal button triggers confirmation modal
• Optionally disable “Appeal” if the listing hasn’t been updated since being blocked
• After a successful appeal, update the listing banner and show a green success alert

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Listing - Appeal Blocked Listing #40

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