feat(ios): delete right after a dictation takes all of it back

App/BlurtiOS/BlurtiOSCore/KeyboardModel+Phase.swift

@@ -87,7 +87,9 @@ extension KeyboardModel {
     SharedStore.remove(forKey: BlurtShared.Key.result)
     // Joined against the live text before the cursor, not the press-time
     // snapshot: the user may have typed since.
-    proxy.insertText(InsertionSeparator.withLeadingSeparator(result.text, after: proxy.documentContextBeforeInput))
+    let inserted = InsertionSeparator.withLeadingSeparator(result.text, after: proxy.documentContextBeforeInput)
+    proxy.insertText(inserted)
+    lastInsertion = inserted
     resultLandedAt = Date()
     // Not typing, so not the term field's to claim.
     if termDraft != nil { termHostBaseline = proxy.documentContextBeforeInput ?? "" }

App/BlurtiOS/BlurtiOSCore/KeyboardModel+Typing.swift

@@ -21,17 +21,28 @@ extension KeyboardModel {
   /// highlighted: the picture follows at once, not on the host's next
   /// notification.
   private func typedIntoHost() {
+    lastInsertion = nil
     readSelection()
   }
 
+  /// Delete right after a dictation takes back all of it — but only while the
+  /// caret still sits at its end with nothing highlighted. A moved caret, a
+  /// selection, or a host that shows less context than the dictation's length
+  /// falls back to deleting one character.
   package func deleteBackward() {
     UIDevice.current.playInputClick()
     if termDraft != nil {
       _ = termDraft?.popLast()
       updateShift()
       return
     }
-    proxy?.deleteBackward()
+    if let inserted = lastInsertion, let proxy, (proxy.selectedText ?? "").isEmpty,
+      proxy.documentContextBeforeInput?.hasSuffix(inserted) == true
+    {
+      for _ in inserted { proxy.deleteBackward() }
+    } else {
+      proxy?.deleteBackward()
+    }
     typedIntoHost()
   }
 

App/BlurtiOS/BlurtiOSCore/KeyboardModel.swift

@@ -67,6 +67,9 @@ package final class KeyboardModel {
   @ObservationIgnored package var gate = DictationKeyGate()
   @ObservationIgnored package let clockStart = ContinuousClock.now
   @ObservationIgnored package var lastResultID: UUID?
+  /// What the last dictation put in the field, separator included, so one
+  /// delete takes the whole of it back. Any keystroke into the host clears it.
+  @ObservationIgnored package var lastInsertion: String?
   @ObservationIgnored private var heartbeat: Task<Void, Never>?
   @ObservationIgnored package var lastSpaceAt: ContinuousClock.Instant?
   @ObservationIgnored package var noticeDwell: Task<Void, Never>?

App/BlurtiOS/BlurtiOSTests/ProtocolTests.swift

@@ -210,6 +210,45 @@ struct KeyboardModelProtocolTests {
     #expect(proxy.before == "Hi one four")
   }
 
+  @Test("delete right after a dictation takes all of it back; otherwise one character")
+  func deleteTakesBackDictation() {
+    let suite = ScratchSuite()
+    defer { suite.tearDown() }
+    let rig = KeyboardRig()
+    let model = rig.model
+    let proxy = rig.proxy
+    func deliver(_ text: String) {
+      SharedStore.write(
+        DictationResult(id: UUID(), text: text, deliveredAt: Date(), recipient: nil),
+        forKey: BlurtShared.Key.result)
+      model.resultArrived()
+    }
+    proxy.before = "Hi"
+    deliver("there friend")
+    #expect(proxy.before == "Hi there friend")
+    model.deleteBackward()
+    #expect(proxy.before == "Hi")
+    // Only once: the next delete is a character again.
+    model.deleteBackward()
+    #expect(proxy.before == "H")
+
+    // Typing after the dictation makes delete a character again.
+    deliver("again")
+    model.type("!")
+    model.deleteBackward()
+    #expect(proxy.before == "H again")
+
+    // So does a caret that no longer sits at the dictation's end, or a selection.
+    deliver("moved")
+    proxy.before += "x"
+    model.deleteBackward()
+    #expect(proxy.before == "H again moved")
+    deliver("chosen")
+    proxy.selected = "chosen"
+    model.deleteBackward()
+    #expect(proxy.before == "H again moved chose")
+  }
+
   @Test("the term field never claims a cursor move or a selection")
   func termFieldIgnoresCursorMoves() {
     let suite = ScratchSuite()