Display persistant command input on server buffer

This commit changes the composer to not be read-only on the server
buffer, which tells the user that they can send commands from that view.

On the server buffer, the placeholder is changed to
"Type a command (see /help)", which indicates to the user that this buffer
only accepts commands, and gives them a hint for how to learn what
commands are available.

Implements: https://todo.sr.ht/~emersion/gamja/38

components/app.js

@@ -1759,13 +1759,15 @@ export default class App extends Component {
 		}
 
 		let composerReadOnly = false;
-		if (activeBuffer && activeBuffer.type === BufferType.SERVER) {
-			composerReadOnly = true;
-		}
 		if (activeServer && activeServer.status !== ServerStatus.REGISTERED) {
 			composerReadOnly = true;
 		}
 
+		let commandOnly = false
+		if (activeBuffer && activeBuffer.type === BufferType.SERVER) {
+			commandOnly = true
+		}
+
 		return html`
 			<section
 					id="buffer-list"
@@ -1813,6 +1815,7 @@ export default class App extends Component {
 				readOnly=${composerReadOnly}
 				onSubmit=${this.handleComposerSubmit}
 				autocomplete=${this.autocomplete}
+				commandOnly=${commandOnly}
 			/>
 			${dialog}
 			${error}

components/composer.js

@@ -143,7 +143,7 @@ export default class Composer extends Component {
 			return;
 		}
 
-		if (this.props.readOnly && event.key !== "/") {
+		if (this.props.readOnly || (this.props.commandOnly && event.key !== "/")) {
 			return;
 		}
 
@@ -201,6 +201,11 @@ export default class Composer extends Component {
 			className = "read-only";
 		}
 
+		let placeholder = "Type a message";
+		if (this.props.commandOnly) {
+			placeholder = "Type a command (see /help)";
+		}
+
 		return html`
 			<form
 				id="composer"
@@ -214,7 +219,7 @@ export default class Composer extends Component {
 					ref=${this.textInput}
 					value=${this.state.text}
 					autocomplete="off"
-					placeholder="Type a message"
+					placeholder=${placeholder}
 					enterkeyhint="send"
 					onKeyDown=${this.handleInputKeyDown}
 				/>