chore: rename quicproquo → quicprochat in Rust workspace

Rename all crate directories, package names, binary names, proto
package/module paths, ALPN strings, env var prefixes, config filenames,
mDNS service names, and plugin ABI symbols from quicproquo/qpq to
quicprochat/qpc.

crates/quicprochat-client/src/client/display.rs

@@ -0,0 +1,82 @@
+//! Terminal display helpers for the REPL.
+
+use super::conversation::StoredMessage;
+use super::session::SessionState;
+
+// ANSI color codes
+const RESET: &str = "\x1b[0m";
+const BOLD: &str = "\x1b[1m";
+const DIM: &str = "\x1b[2m";
+const GREEN: &str = "\x1b[32m";
+const CYAN: &str = "\x1b[36m";
+const YELLOW: &str = "\x1b[33m";
+
+/// Print the REPL prompt showing the active conversation and unread count.
+pub fn print_prompt(session: &SessionState) {
+    use std::io::Write;
+    let name = session
+        .active_display_name()
+        .unwrap_or_else(|| "no conversation".into());
+    let unread = session.total_unread();
+    if unread > 0 {
+        print!("{DIM}[{RESET}{BOLD}{name}{RESET} {YELLOW}{unread} unread{RESET}{DIM}]{RESET} > ");
+    } else {
+        print!("{DIM}[{RESET}{BOLD}{name}{RESET}{DIM}]{RESET} > ");
+    }
+    let _ = std::io::stdout().flush();
+}
+
+/// Print an incoming or outgoing message.
+pub fn print_message(msg: &StoredMessage) {
+    let body = if msg.msg_type == "reaction" {
+        format!("reacted {}", msg.body)
+    } else {
+        msg.body.clone()
+    };
+    if msg.is_outgoing {
+        println!("\r{GREEN}> {body}{RESET}");
+    } else {
+        let fallback = hex::encode(&msg.sender_key[..4]);
+        let sender = msg.sender_name.as_deref().unwrap_or(&fallback);
+        println!("\r{CYAN}{BOLD}[{sender}]{RESET} {body}");
+    }
+}
+
+/// Print a message received in real-time (clears current line first).
+pub fn print_incoming(sender: &str, body: &str) {
+    use std::io::Write;
+    // Clear current line, print message, then re-show prompt context
+    print!("\r\x1b[2K");
+    println!("{CYAN}{BOLD}[{sender}]{RESET} {body}");
+    let _ = std::io::stdout().flush();
+}
+
+/// Print a system/status message.
+pub fn print_status(msg: &str) {
+    println!("{DIM}  {msg}{RESET}");
+}
+
+/// Print a transient typing indicator (clears current line first).
+pub fn print_typing(sender: &str) {
+    use std::io::Write;
+    print!("\r\x1b[2K");
+    println!("{DIM}  {sender} is typing...{RESET}");
+    let _ = std::io::stdout().flush();
+}
+
+/// Print an error message.
+pub fn print_error(msg: &str) {
+    println!("{YELLOW}  error: {msg}{RESET}");
+}
+
+/// Format a conversation list entry for `/list`.
+pub fn format_conv_line(display_name: &str, kind: &str, unread: u32, members: usize) -> String {
+    let unread_str = if unread > 0 {
+        format!(" {YELLOW}({unread} new){RESET}")
+    } else {
+        String::new()
+    };
+    format!(
+        "  {BOLD}{display_name}{RESET} {DIM}[{kind}, {members} members]{RESET}{unread_str}"
+    )
+}