Address Jack review on quote-in-composer (#1570).

Add content.message.quote to the 30-locale catalog; use a plain sender
header (no @) so quotes do not re-ping; drop the shared draft when the
composer target changes; and only skip the newline insert after a real
trailing newline (not a trailing space).

bitchat/Services/MessageClipboard.swift

@@ -28,12 +28,15 @@ enum MessageClipboard {
     }
 
     /// Builds a composer-ready quote block (`> line` per line, trailing blank).
+    /// Sender header is plain text (`> alice:`), not `@alice`, so quoting does
+    /// not re-fire mention notifications for the quoted person or for names
+    /// inside the quoted body (those stay behind `> ` and are not live tokens).
     static func quoteForComposer(_ content: String, sender: String?) -> String {
         let body = content.trimmingCharacters(in: .whitespacesAndNewlines)
         guard !body.isEmpty else { return "" }
         let header: String
         if let sender, !sender.isEmpty, sender != "system" {
-            header = "> @\(sender):\n"
+            header = "> \(sender):\n"
         } else {
             header = ""
         }
@@ -45,11 +48,13 @@ enum MessageClipboard {
     }
 
     /// Appends a quote to an existing composer draft without wiping it.
+    /// Only a trailing newline skips inserting another separator — a trailing
+    /// space must still get a newline so the quote marker starts its own line.
     static func appendQuote(to draft: String, content: String, sender: String?) -> String {
         let quote = quoteForComposer(content, sender: sender)
         guard !quote.isEmpty else { return draft }
         if draft.isEmpty { return quote }
-        if draft.hasSuffix("\n") || draft.hasSuffix(" ") {
+        if draft.hasSuffix("\n") {
             return draft + quote
         }
         return draft + "\n" + quote

bitchat/Views/ContentView.swift

@@ -254,12 +254,17 @@ struct ContentView: View {
         .frame(minWidth: 600, minHeight: 400)
         #endif
         .onChange(of: selectedPrivatePeerID) { newValue in
+            // Shared composer draft must not travel across conversation
+            // targets (quoting a DM then opening public would otherwise
+            // one-tap-broadcast private content).
+            messageText = ""
             if newValue != nil {
                 showSidebar = true
             }
             sharedContentImportModel.updateDestination(sharedContentDestination)
         }
         .onChange(of: locationChannelsModel.selectedChannel) { _ in
+            messageText = ""
             sharedContentImportModel.updateDestination(sharedContentDestination)
         }
         .sheet(

bitchatTests/Services/MessageClipboardTests.swift

@@ -5,7 +5,7 @@ import Testing
 struct MessageClipboardTests {
     @Test func quoteWrapsEachLineAndAddsSender() {
         let quoted = MessageClipboard.quoteForComposer("hello\nworld", sender: "alice")
-        #expect(quoted == "> @alice:\n> hello\n> world\n\n")
+        #expect(quoted == "> alice:\n> hello\n> world\n\n")
     }
 
     @Test func quoteSkipsSystemSenderHeader() {
@@ -23,7 +23,7 @@ struct MessageClipboardTests {
             content: "prior message",
             sender: "bob"
         )
-        #expect(result == "already typing\n> @bob:\n> prior message\n\n")
+        #expect(result == "already typing\n> bob:\n> prior message\n\n")
     }
 
     @Test func appendQuoteOntoEmptyDraft() {
@@ -32,6 +32,15 @@ struct MessageClipboardTests {
             content: "solo",
             sender: "carol"
         )
-        #expect(result == "> @carol:\n> solo\n\n")
+        #expect(result == "> carol:\n> solo\n\n")
+    }
+
+    @Test func appendQuoteAfterTrailingSpaceStartsNewLine() {
+        let result = MessageClipboard.appendQuote(
+            to: "draft with space ",
+            content: "quoted",
+            sender: "dana"
+        )
+        #expect(result == "draft with space \n> dana:\n> quoted\n\n")
     }
 }