Recap editor: Regenerate recap (re-run LLM on corrected transcript)

Adds a 'Regenerate recap' action so corrected speaker names flow into freshly
written summaries/extras (not just find-replaced). regenerate() commits the
corrections (rewrite speakers.json + reconcile voiceprints), re-runs RecapAnalyzer
on the corrected transcript via the gateway LLM, and rewrites recap.json +
transcript.md + recap.html. save() and regenerate() share commitCorrections();
both rebaseline the speaker set afterward so further edits map cleanly. Editor view
gains the button + progress spinner; RecapEditModel takes the gateway baseURL/skipTLS.

52/52 XCTest; builds clean.

Ten31Transcripts/Session/SessionController.swift

@@ -433,7 +433,9 @@ final class SessionController: ObservableObject {
     /// 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 }
+              let model = RecapEditModel(folder: folder, voiceprints: voiceprints,
+                                         baseURL: settings.backendBaseURL, skipTLS: settings.skipTLSVerification)
+        else { return }
         EditorWindow.shared.show(model: model)
     }