feat: a trash for tickets

Deleting a ticket now sends it to the trash, for whoever opened it or an
admin: it disappears from boards, searches and statistics, cannot change,
and comes back from the ticket page or the trash page for 30 days. After
that it is deleted for good with the usual cascade.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/api/schema.gql

@@ -439,6 +439,9 @@ type Issue {
   storyPoints: Int
   title: String!
 
+  """In the trash since then; null when it is not"""
+  trashedAt: String
+
   """A ticket type id of the project's settings"""
   type: String!
   updatedAt: String!
@@ -656,6 +659,9 @@ type Mutation {
   removeChecklistItem(issueId: ID!, itemId: ID!): CommandResult!
   removeProjectMember(projectId: ID!, userId: ID!): CommandResult!
 
+  """Back from the trash"""
+  restoreIssue(issueId: ID!): CommandResult!
+
   """Save the current board filters under a name (members of the project)"""
   saveFilter(input: SaveFilterInput!): ID!
 
@@ -675,6 +681,11 @@ type Mutation {
 
   """Send a ping now and tell how it went"""
   testWebhook(webhookId: ID!): WebhookDelivery!
+
+  """
+  To the trash (whoever opened it, or an owner/admin): hidden everywhere, deleted for good after 30 days
+  """
+  trashIssue(issueId: ID!): CommandResult!
   unlinkIssues(input: LinkIssuesInput!): CommandResult!
 
   """Stop following a ticket"""
@@ -937,6 +948,9 @@ type Query {
   """
   sprints(projectId: ID!): [Sprint!]!
 
+  """A project's tickets in the trash, newest first"""
+  trash(projectId: ID!): [Issue!]!
+
   """Planned releases of all my projects, soonest target date first"""
   upcomingReleases(limit: Int! = 10): [Release!]!
   user(id: String!): User