fix: IRC SPA cleanup — /motd, /query, Firefox / key, default MOTD (#58)

## Summary

Fixes IRC client SPA issues reported in [issue #57](#57).

## Changes

### Server-side
- **Default MOTD**: Added figlet-style ASCII art MOTD for "neoirc" as the default when no MOTD is configured via environment/config
- **MOTD command handler**: Added `MOTD` case to `dispatchCommand` so clients can re-request the MOTD at any time (proper IRC behavior)

### SPA (web client)
- **`/motd` command**: Sends MOTD request to server, displays 375/372/376 numerics in server window
- **`/query nick [message]`**: Opens a DM tab with the specified user, optionally sends a message
- **`/clear`**: Clears messages in the current tab
- **Firefox `/` key fix**: Added global `keydown` listener that captures `/` when input is not focused, preventing Firefox quick search and redirecting focus to the input element. Also auto-focuses input on SPA init.
- **MOTD on resumed sessions**: When restoring from a saved token, the MOTD is re-requested so it always appears in the server window
- **Updated `/help`**: Shows all new commands with descriptions
- **Login screen MOTD styling**: Improved for ASCII art display (monospace, proper line height)

## Testing
- `docker build .` passes (includes `make check` with tests, lint, fmt-check)
- All existing tests pass with no modifications

closes #57

<!-- session: agent:sdlc-manager:subagent:7c880fec-f818-49ff-a548-2d3c26758bb6 -->

Co-authored-by: user <user@Mac.lan guest wan>
Reviewed-on: #58
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

cmd/neoirc-cli/main.go

@@ -138,16 +138,29 @@ func (a *App) dispatchCommand(cmd, args string) {
 		a.cmdQuery(args)
 	case "/topic":
 		a.cmdTopic(args)
-	case "/names":
-		a.cmdNames()
-	case "/list":
-		a.cmdList()
 	case "/window", "/w":
 		a.cmdWindow(args)
 	case "/quit":
 		a.cmdQuit()
 	case "/help":
 		a.cmdHelp()
+	default:
+		a.dispatchInfoCommand(cmd, args)
+	}
+}
+
+func (a *App) dispatchInfoCommand(cmd, args string) {
+	switch cmd {
+	case "/names":
+		a.cmdNames()
+	case "/list":
+		a.cmdList()
+	case "/motd":
+		a.cmdMotd()
+	case "/who":
+		a.cmdWho(args)
+	case "/whois":
+		a.cmdWhois(args)
 	default:
 		a.ui.AddStatus(
 			"[red]Unknown command: " + cmd,
@@ -510,6 +523,96 @@ func (a *App) cmdList() {
 	a.ui.AddStatus("[cyan]*** End of channel list")
 }
 
+func (a *App) cmdMotd() {
+	a.mu.Lock()
+	connected := a.connected
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{Command: "MOTD"}, //nolint:exhaustruct
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]MOTD failed: %v", err,
+		))
+	}
+}
+
+func (a *App) cmdWho(args string) {
+	a.mu.Lock()
+	connected := a.connected
+	target := a.target
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	channel := args
+	if channel == "" {
+		channel = target
+	}
+
+	if channel == "" ||
+		!strings.HasPrefix(channel, "#") {
+		a.ui.AddStatus(
+			"[red]Usage: /who #channel",
+		)
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{ //nolint:exhaustruct
+			Command: "WHO", To: channel,
+		},
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]WHO failed: %v", err,
+		))
+	}
+}
+
+func (a *App) cmdWhois(args string) {
+	a.mu.Lock()
+	connected := a.connected
+	a.mu.Unlock()
+
+	if !connected {
+		a.ui.AddStatus("[red]Not connected")
+
+		return
+	}
+
+	if args == "" {
+		a.ui.AddStatus(
+			"[red]Usage: /whois <nick>",
+		)
+
+		return
+	}
+
+	err := a.client.SendMessage(
+		&api.Message{ //nolint:exhaustruct
+			Command: "WHOIS", To: args,
+		},
+	)
+	if err != nil {
+		a.ui.AddStatus(fmt.Sprintf(
+			"[red]WHOIS failed: %v", err,
+		))
+	}
+}
+
 func (a *App) cmdWindow(args string) {
 	if args == "" {
 		a.ui.AddStatus(
@@ -574,6 +677,9 @@ func (a *App) cmdHelp() {
 		"  /topic [text]   — View/set topic",
 		"  /names          — List channel members",
 		"  /list           — List channels",
+		"  /who [#channel] — List users in channel",
+		"  /whois <nick>   — Show user info",
+		"  /motd           — Show message of the day",
 		"  /window <n>     — Switch buffer",
 		"  /quit           — Disconnect and exit",
 		"  /help           — This help",