feat(web): /install shell script + real curl one-liner on landing

Landing page showed \`curl -fsSL claudemesh.sh/install | bash\` but
the domain didn't resolve, so anyone copy-pasting got a DNS error.

Ship:
- apps/web/src/app/install/route.ts: GET returns an auditable bash
  installer (Node preflight, npm install -g claudemesh-cli, runs
  claudemesh install, prints next steps, colored output). No Node
  auto-install — fails clean if missing with a pointer.
- apps/web/src/proxy.ts: exclude /install from the i18n matcher so
  Next.js returns the shell script unmangled.
- hero.tsx + features.tsx: swap claudemesh.sh → claudemesh.com.

Test: curl http://localhost:3000/install | bash -n → OK.
Content-Type: text/x-shellscript; charset=utf-8.

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

apps/web/src/app/install/route.ts

@@ -0,0 +1,100 @@
+/**
+ * GET /install — serves a shell installer for claudemesh-cli.
+ *
+ * Intended to be piped into bash:
+ *   curl -fsSL https://claudemesh.com/install | bash
+ *
+ * The script is kept short + auditable. It does not try to install
+ * Node for the user — it checks for a compatible Node + npm and
+ * directs them to install Node themselves if missing. Running `bash`
+ * against a domain you do not fully trust is always a risk; publishing
+ * the script this way (rather than obfuscating it behind a binary
+ * blob) lets security-conscious users inspect before executing.
+ */
+
+const SCRIPT = `#!/usr/bin/env bash
+# claudemesh-cli installer
+# Source: https://claudemesh.com/install
+# Audit: curl -fsSL https://claudemesh.com/install | less
+set -euo pipefail
+
+RED=$'\\033[31m'; GREEN=$'\\033[32m'; DIM=$'\\033[2m'; BOLD=$'\\033[1m'; RESET=$'\\033[0m'
+
+say() { printf "%s\\n" "$*"; }
+ok()  { printf "%s✓%s %s\\n" "\${GREEN}" "\${RESET}" "$*"; }
+err() { printf "%s✗%s %s\\n" "\${RED}" "\${RESET}" "$*" >&2; }
+
+say ""
+say "\${BOLD}claudemesh-cli installer\${RESET}"
+say "$(printf '%.0s─' {1..40})"
+
+# --- preflight ------------------------------------------------------
+
+if ! command -v node >/dev/null 2>&1; then
+  err "Node.js is not installed."
+  say "   Install Node.js 20 or newer: \${BOLD}https://nodejs.org\${RESET}"
+  say "   Or via nvm: \${DIM}curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash\${RESET}"
+  exit 1
+fi
+
+NODE_MAJOR=$(node -p "process.versions.node.split('.')[0]")
+if [ "$NODE_MAJOR" -lt 20 ]; then
+  err "Node.js $(node -v) is too old — claudemesh-cli needs >= 20."
+  say "   Upgrade: \${BOLD}https://nodejs.org\${RESET}"
+  exit 1
+fi
+ok "Node.js $(node -v)"
+
+if ! command -v npm >/dev/null 2>&1; then
+  err "npm is not installed (usually ships with Node)."
+  exit 1
+fi
+ok "npm $(npm -v)"
+
+# --- install --------------------------------------------------------
+
+say ""
+say "Installing \${BOLD}claudemesh-cli\${RESET} from npm…"
+if ! npm install -g claudemesh-cli; then
+  err "npm install failed."
+  say "   If this is a permissions error on macOS/Linux, try:"
+  say "   \${DIM}sudo npm install -g claudemesh-cli\${RESET}"
+  say "   or configure npm to use a user-owned prefix:"
+  say "   \${DIM}https://docs.npmjs.com/resolving-eacces-permissions-errors\${RESET}"
+  exit 1
+fi
+ok "claudemesh-cli installed ($(claudemesh --version))"
+
+# --- register MCP + hooks ------------------------------------------
+
+say ""
+say "Registering Claude Code MCP server + status hooks…"
+if ! claudemesh install; then
+  err "claudemesh install failed — run it manually to see the error."
+  exit 1
+fi
+
+# --- done -----------------------------------------------------------
+
+say ""
+say "\${GREEN}\${BOLD}Done.\${RESET}"
+say ""
+say "Next steps:"
+say "  1. Restart Claude Code so the MCP tools appear."
+say "  2. Join a mesh:      \${BOLD}claudemesh join <invite-url>\${RESET}"
+say "  3. Launch with push: \${BOLD}claudemesh launch\${RESET}"
+say ""
+say "Need an invite? Visit \${BOLD}https://claudemesh.com\${RESET}"
+say ""
+`;
+
+export function GET(): Response {
+  return new Response(SCRIPT, {
+    status: 200,
+    headers: {
+      "Content-Type": "text/x-shellscript; charset=utf-8",
+      "Cache-Control": "public, max-age=300, s-maxage=600",
+      "X-Content-Type-Options": "nosniff",
+    },
+  });
+}