Speaker corrections: rename / merge / reassign + voice learning

Native editor to fix speaker-ID errors after transcription (modeled on recap-relay's
correction UX): rename a speaker in the legend, merge two speakers, or reassign an
individual transcript line. Saving rewrites speakers.json, re-renders transcript.md +
recap.html, and updates the voiceprint memory — so a correction compounds: naming an
"Unknown" speaker teaches that voice for future calls.

- SpeakerEditing (pure, tested): replaceSpeaker (rename = merge-onto-existing),
  reassign, netNameMap (compose ops), and remap (apply a name map to a recap's
  structured fields + whole-word free text, so summaries/extras update without re-LLM).
- RecapEditModel (@MainActor): loads speakers.json (+ optional recap.json +
  cluster_fingerprints.json); on save writes the resolved speakers.json, re-renders,
  and reconciles voiceprints — merge keeps the survivor's print; rename/name-an-Unknown
  enrolls the cluster's fingerprint under the new name.
- TranscriptEditorView (SwiftUI) + EditorWindow (AppKit window for the LSUIElement app);
  menu gains "Edit speakers".
- Pipeline now persists cluster_fingerprints.json (every cluster incl. Unknown) and
  recap.json (RecapFile) so the editor can learn voices + re-render offline.
- RecapModels made Codable; TranscriptAssembler exposes allFingerprints;
  VoiceprintStore gains enroll() + merge().

52/52 XCTest (6 new, incl. a full rename→artifacts→voiceprint round-trip on disk).

Ten31Transcripts/Session/SessionController.swift

@@ -406,6 +406,7 @@ final class SessionController: ObservableObject {
         guard let result = try? await analyzer.recap(file: speakers) else { return }
         let title = Self.recapTitle(app: inputs.app, sessionId: inputs.sessionId)
         try? RecapRenderer.write(file: speakers, result: result, title: title, to: inputs.folder)
+        try? RecapFile(title: title, result: result).write(to: inputs.folder.appendingPathComponent("recap.json"))
         let url = inputs.folder.appendingPathComponent("recap.html")
         if FileManager.default.fileExists(atPath: url.path) { self.recapURL = url }
     }
@@ -421,6 +422,21 @@ final class SessionController: ObservableObject {
         return "\(appName) call — \(date) \(time)".trimmingCharacters(in: .whitespaces)
     }
 
+    // MARK: - Speaker corrections
+
+    /// True once the last session has a transcribed `speakers.json` to correct.
+    var canEditSpeakers: Bool {
+        guard let folder = lastSession?.folder else { return false }
+        return FileManager.default.fileExists(atPath: folder.appendingPathComponent("speakers.json").path)
+    }
+
+    /// Open the speaker-correction editor for the last session.
+    func editLastSession() {
+        guard let folder = lastSession?.folder,
+              let model = RecapEditModel(folder: folder, voiceprints: voiceprints) else { return }
+        EditorWindow.shared.show(model: model)
+    }
+
     private func fail(_ message: String) {
         recorder = nil
         visualCapture = nil   // recorder.start() failed before visual started; nothing running