chore: comment cleanup pass ahead of open-sourcing

Removes leftover debug scaffolding (stray Console.WriteLine/NSLog traces,
dead nick_buf_ptr, a no-op --print-config flag now implemented for real),
fixes stale/misleading comments (channel passwords are no longer a "future
M5+" feature, a wrong cross-reference, a stale TlsContext::close() mention,
an incomplete BanRecord::subject_type doc, and a smoke test pointing at a
build/m1-dev preset that no longer exists), strips internal M1-M5 milestone
jargon from comments now that the roadmap is done, trims comments that just
restated the following line, and consolidates a few "why" explanations that
were duplicated 2-3 times in the same file.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

clients/apple/macOS/VoiceCatMac/Windows/ConnectWindowController.swift

@@ -44,7 +44,6 @@ final class ConnectWindowController: NSWindowController, NSWindowDelegate {
     private func buildUI() {
         guard let contentView = window?.contentView else { return }
 
-        // Server list
         let col = NSTableColumn(identifier: NSUserInterfaceItemIdentifier("server"))
         col.title = "Saved Servers"
         serverTableView.addTableColumn(col)
@@ -61,7 +60,6 @@ final class ConnectWindowController: NSWindowController, NSWindowDelegate {
         serverScrollView.translatesAutoresizingMaskIntoConstraints = false
         contentView.addSubview(serverScrollView)
 
-        // Buttons row
         configureButton(addButton, title: "Add…", action: #selector(addClicked))
         configureButton(editButton, title: "Edit…", action: #selector(editClicked))
         configureButton(removeButton, title: "Remove", action: #selector(removeClicked))
@@ -72,13 +70,11 @@ final class ConnectWindowController: NSWindowController, NSWindowDelegate {
         buttonStack.translatesAutoresizingMaskIntoConstraints = false
         contentView.addSubview(buttonStack)
 
-        // Status
         statusLabel.translatesAutoresizingMaskIntoConstraints = false
         statusLabel.textColor = .secondaryLabelColor
         statusLabel.setAccessibilityLabel("Connection status")
         contentView.addSubview(statusLabel)
 
-        // Connect button
         connectButton.title = "Connect"
         connectButton.bezelStyle = .rounded
         connectButton.keyEquivalent = "\r"
@@ -376,7 +372,3 @@ extension ConnectWindowController: NSTableViewDataSource, NSTableViewDelegate {
         return cell
     }
 }
-
-// MARK: - Helper
-
-