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/UI/TranscriptEditorView.swift

@@ -94,11 +94,15 @@ struct TranscriptEditorView: View {
     // MARK: - Footer
 
     private var footer: some View {
-        HStack {
+        HStack(spacing: 10) {
             Button("Save corrections") { model.save() }
                 .keyboardShortcut("s", modifiers: .command)
-                .disabled(!model.dirty)
-            if let s = model.status { Text(s).font(.caption).foregroundStyle(.green) }
+                .disabled(!model.dirty || model.regenerating)
+            Button("Regenerate recap") { Task { await model.regenerate() } }
+                .help("Re-run the analysis on the corrected transcript so summaries use the fixed names.")
+                .disabled(model.regenerating)
+            if model.regenerating { ProgressView().controlSize(.small) }
+            if let s = model.status { Text(s).font(.caption).foregroundStyle(.secondary) }
             Spacer()
             if let recap = recapURL {
                 Button("Open recap") { NSWorkspace.shared.open(recap) }