[FEATURE] Syntax highlight slash commands in Remote Control / Web client

Feature Request

When using Claude Code via Remote Control (claude.ai/code), slash commands (e.g., /commit, /review-pr, /memory) are rendered as plain text in the input area. There is no visual distinction between a slash command and regular prose.

Problem

In the interactive CLI, the / menu provides filtering and visual affordance, making it clear you're invoking a command. In the Remote Control / web client, there's no equivalent cue — slash commands look identical to any other text. This makes it easy to lose track of whether you're typing a command or a message, especially during fast workflow switching.

Proposed Solution

Apply syntax highlighting or visual styling to recognized slash commands in the Remote Control input area:

• Detect /command-name patterns as the user types
• Apply a distinct style (e.g., monospace font, colored text, subtle background) so it's immediately clear a command is being invoked
• Optionally show an autocomplete/menu similar to the CLI experience

Why It Matters

• Workflow confidence — a visual cue confirms you're in the right mode before hitting enter
• Discoverability — new users can see that / triggers something special
• Parity with CLI — the terminal experience already has this affordance; the web client should match

Environment

• Mode: Remote Control (web client at claude.ai/code)
• Platform: macOS (but applies to all Remote Control clients)