feat(cli): claudemesh launch command with transparency banner (v0.1.2)

Adds `claudemesh launch [args]` that spawns Claude Code with
--dangerously-load-development-channels server:claudemesh so peer
messages arrive as <channel> system reminders mid-turn instead of
pull-only via check_messages. Windows uses shell:true to resolve
claude.cmd from PATHEXT.

Prints an info banner before spawning that explains the channel's
scope (peer text injection only), the trust model (treat as
untrusted input), and that existing tool-approval prompts remain
the safety net. --quiet skips the banner.

Install output now mentions `claudemesh launch` as the recommended
launch path; plain `claude` still works for pull-only mode.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli/src/commands/install.ts

@@ -307,6 +307,17 @@ export function runInstall(args: string[] = []): void {
   console.log(
     `Next: ${bold("claudemesh join https://claudemesh.com/join/<token>")}`,
   );
+  console.log("");
+  console.log(
+    yellow("⚠  For real-time push messages from peers, launch with:"),
+  );
+  console.log(
+    `     ${bold("claudemesh launch")}` +
+      dim("    (or: claude --dangerously-load-development-channels server:claudemesh)"),
+  );
+  console.log(
+    dim("   Plain `claude` still works — messages are then pull-only via check_messages."),
+  );
 }
 
 export function runUninstall(): void {