fix: push patchset views directly instead of by route

Tapping a patch failed with "no matching navigationDestination declaration
visible from the location of the link".

MailingListDetailView is presented from four places, but only the More tab and
Lookup declare a MoreRoute destination. Reached from a project, via
ProjectMailingListView, there is no such destination in the surrounding stack,
so a NavigationLink carrying MoreRoute.patchset had nowhere to resolve. The
thread rows beside it already use the closure form for exactly this reason.

Push PatchsetDetailView directly, from the rows and from the version-chain
links inside the detail view, which inherits whatever stack presented it. That
leaves MoreRoute.patchset with no users, so it and its two destinations are
removed rather than left as a route nothing links to.

Neither the compiler nor the tests catch this: it is a runtime SwiftUI
resolution failure.

4 files changed, 15 insertions, 8 deletions

diff --git a/Hutch/App/RootView.swift b/Hutch/App/RootView.swift
index 59d7caa..1ae4651 100644
--- a/Hutch/App/RootView.swift
+++ b/Hutch/App/RootView.swift
@@ -439,7 +439,6 @@ enum MoreRoute: Hashable {
     case projectDashboard(id: String, title: String?)
     case mailingList(InboxMailingListReference)
     case thread(InboxThreadSummary)
-    case patchset(id: Int, listName: String?)
     case manPageBrowser
     case manPage(URL)
 }
@@ -473,8 +472,6 @@ private struct MoreNavigationRoot: View {
                     ProjectDashboardDeepLinkView(projectID: id, title: title)
                 case .mailingList(let mailingList):
                     MailingListDetailView(mailingList: mailingList)
-                case .patchset(let id, let listName):
-                    PatchsetDetailView(patchsetID: id, listName: listName)
                 case .thread(let thread):
                     ThreadDetailView(
                         thread: thread,
diff --git a/Hutch/Views/Lookup/LookupView.swift b/Hutch/Views/Lookup/LookupView.swift
index b52bb3f..2a26282 100644
--- a/Hutch/Views/Lookup/LookupView.swift
+++ b/Hutch/Views/Lookup/LookupView.swift
@@ -465,8 +465,6 @@ struct LookupView: View {
                     ProjectDashboardDeepLinkView(projectID: id, title: title)
                 case .mailingList(let mailingList):
                     MailingListDetailView(mailingList: mailingList)
-                case .patchset(let id, let listName):
-                    PatchsetDetailView(patchsetID: id, listName: listName)
                 case .thread(let thread):
                     ThreadDetailView(
                         thread: thread,
diff --git a/Hutch/Views/Patchsets/PatchsetDetailView.swift b/Hutch/Views/Patchsets/PatchsetDetailView.swift
index d76aab4..7bc5630 100644
--- a/Hutch/Views/Patchsets/PatchsetDetailView.swift
+++ b/Hutch/Views/Patchsets/PatchsetDetailView.swift
@@ -122,8 +122,14 @@ struct PatchsetDetailView: View {
 
             // The version chain matters during review: a superseded series should
             // usually be read at its newest version instead.
+            //
+            // Pushed directly rather than by value, for the same reason as the rows
+            // that lead here — this view inherits whatever stack presented it, and
+            // not all of them declare a MoreRoute destination.
             if let supersededBy = patchset.supersededBy {
-                NavigationLink(value: MoreRoute.patchset(id: supersededBy, listName: listName)) {
+                NavigationLink {
+                    PatchsetDetailView(patchsetID: supersededBy, listName: listName)
+                } label: {
                     SwiftUI.Label("Superseded by a newer version", systemImage: "arrow.right.circle")
                         .font(.subheadline)
                 }
@@ -131,7 +137,9 @@ struct PatchsetDetailView: View {
             }
 
             if let supersedes = patchset.supersedes {
-                NavigationLink(value: MoreRoute.patchset(id: supersedes, listName: listName)) {
+                NavigationLink {
+                    PatchsetDetailView(patchsetID: supersedes, listName: listName)
+                } label: {
                     SwiftUI.Label("Revises an earlier version", systemImage: "arrow.left.circle")
                         .font(.subheadline)
                 }
diff --git a/Hutch/Views/Projects/ProjectMailingListView.swift b/Hutch/Views/Projects/ProjectMailingListView.swift
index 3933bf3..696cf6b 100644
--- a/Hutch/Views/Projects/ProjectMailingListView.swift
+++ b/Hutch/Views/Projects/ProjectMailingListView.swift
@@ -420,7 +420,11 @@ struct MailingListDetailView: View {
 
             if showingPatches(viewModel) {
                 ForEach(viewModel.filteredPatchsets) { patchset in
-                    NavigationLink(value: MoreRoute.patchset(id: patchset.id, listName: mailingList.name)) {
+                    // Pushed directly rather than by value: this view is also shown
+                    // from a project, whose stack declares no MoreRoute destination.
+                    NavigationLink {
+                        PatchsetDetailView(patchsetID: patchset.id, listName: mailingList.name)
+                    } label: {
                         PatchsetRow(patchset: patchset)
                     }
                     .themedRow()