Speaker reconciliation + open/re-process any saved session

Reconciliation (the marry-the-signals layer): after transcription, before the recap,
SpeakerReconciler (1) MERGES non-self clusters whose voiceprints are highly similar
(cosine >= 0.82) — fixes a person split across chunks (the real 1-on-1 failure: one
remote came back as 'MH' + 'Unknown_0'); and (2) NAMES remaining non-self clusters
from transcript CONTENT via the gateway LLM (people addressed by name / self-intros),
conservative + confidence-gated, keeping the placeholder when unrevealed. The
mic-channel self is protected and never reassigned. Voice does the segmentation; the
fingerprint-merge fixes splits; the LLM adds the content signal visual/voiceprint lack.

- SpeakerReconciler: pure cosine merge (tested) + LLM content-naming pass; rewrites
  speakers.json before recap. SessionController.finishBackend shares one model lookup
  for reconcile + recap. Gated by settings.reconcileSpeakers (default on).
- Open saved session: menu 'Open saved session…' → folder picker. Edits it if already
  transcribed, else reconstructs inputs from disk (visual_timeline vision segs +
  channel self-spans) and runs transcribe → reconcile → recap, then opens the editor.
  Lets you evaluate/correct ANY past call, not just the in-memory last one.

Note (from real Signal data): visual naming is unreliable on Signal (sparse, misread
initials, lowercase/center names) — so reconciliation + the editor (which teaches
voiceprints on confirm) carry it; the editor remains the human arbiter. 59/59 XCTest.

Ten31Transcripts/Settings/AppSettings.swift

@@ -53,6 +53,13 @@ final class AppSettings: ObservableObject {
         didSet { defaults.set(recapEnabled, forKey: Keys.recapEnabled) }
     }
 
+    /// Reconcile speaker labels after transcription: merge a person split across
+    /// chunks (same voiceprint) and name placeholder/initial labels from what the
+    /// conversation reveals (gateway LLM). Best-effort.
+    @Published var reconcileSpeakers: Bool {
+        didSet { defaults.set(reconcileSpeakers, forKey: Keys.reconcileSpeakers) }
+    }
+
     /// User-editable recap templates (takeaways categories per meeting type).
     @Published var recapTemplates: [RecapTemplate] {
         didSet { persist(recapTemplates, forKey: Keys.recapTemplates) }
@@ -96,6 +103,7 @@ final class AppSettings: ObservableObject {
         self.selfName = defaults.string(forKey: Keys.selfName) ?? "Me"
         self.autoSendOnStop = defaults.object(forKey: Keys.autoSend) as? Bool ?? false
         self.recapEnabled = defaults.object(forKey: Keys.recapEnabled) as? Bool ?? true
+        self.reconcileSpeakers = defaults.object(forKey: Keys.reconcileSpeakers) as? Bool ?? true
 
         let loaded = (defaults.data(forKey: Keys.recapTemplates))
             .flatMap { try? JSONDecoder().decode([RecapTemplate].self, from: $0) }
@@ -117,6 +125,7 @@ final class AppSettings: ObservableObject {
         static let selfName = "selfName"
         static let autoSend = "autoSendOnStop"
         static let recapEnabled = "recapEnabled"
+        static let reconcileSpeakers = "reconcileSpeakers"
         static let recapTemplates = "recapTemplates"
         static let defaultTemplate = "defaultTemplateId"
     }