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/Recap/RecapModels.swift

@@ -2,7 +2,7 @@ import Foundation
 
 /// One topic section: a contiguous run of transcript entries `[startIndex...endIndex]`
 /// (inclusive, indices into the canonical entries array) with an LLM title + summary.
-struct TopicSection: Equatable {
+struct TopicSection: Equatable, Codable {
     var title: String
     var summary: String
     var startIndex: Int
@@ -12,12 +12,12 @@ struct TopicSection: Equatable {
 /// Structured "meeting extras" extracted from the named transcript. Mirrors
 /// recap-relay's schema; speakers are real names (we already have them from
 /// label-merge), not anonymous cluster ids.
-struct MeetingExtras: Equatable {
-    struct TLDR: Equatable { var summary: String; var primarySpeakers: [String] }
-    struct Decision: Equatable { var statement: String; var agreedBy: [String]; var supportingOffset: Int? }
-    struct ActionItem: Equatable { var description: String; var owner: String?; var dueHint: String?; var supportingOffset: Int? }
-    struct OpenQuestion: Equatable { var question: String; var raisedBy: String? }
-    struct KeyQuote: Equatable { var speaker: String?; var offset: Int?; var quote: String; var whyNotable: String }
+struct MeetingExtras: Equatable, Codable {
+    struct TLDR: Equatable, Codable { var summary: String; var primarySpeakers: [String] }
+    struct Decision: Equatable, Codable { var statement: String; var agreedBy: [String]; var supportingOffset: Int? }
+    struct ActionItem: Equatable, Codable { var description: String; var owner: String?; var dueHint: String?; var supportingOffset: Int? }
+    struct OpenQuestion: Equatable, Codable { var question: String; var raisedBy: String? }
+    struct KeyQuote: Equatable, Codable { var speaker: String?; var offset: Int?; var quote: String; var whyNotable: String }
 
     var tldr: TLDR
     var decisions: [Decision]
@@ -32,7 +32,24 @@ struct MeetingExtras: Equatable {
 
 /// The assembled recap for one session: the topic sections + (optional) extras,
 /// over the session's transcript. Rendered to `transcript.md` / `recap.html`.
-struct RecapResult: Equatable {
+struct RecapResult: Equatable, Codable {
     var sections: [TopicSection]
     var extras: MeetingExtras?
 }
+
+/// Persisted `recap.json` — the recap result plus its title, so the speaker editor
+/// can re-render `recap.html` / `transcript.md` after corrections without re-calling
+/// the LLM (a "Regenerate" action re-runs analysis when the user wants fresh summaries).
+struct RecapFile: Equatable, Codable {
+    var title: String
+    var result: RecapResult
+
+    func write(to url: URL) throws {
+        let enc = JSONEncoder(); enc.outputFormatting = [.prettyPrinted, .sortedKeys]
+        try enc.encode(self).write(to: url)
+    }
+    static func read(from url: URL) -> RecapFile? {
+        guard let data = try? Data(contentsOf: url) else { return nil }
+        return try? JSONDecoder().decode(RecapFile.self, from: data)
+    }
+}