feat: add Cursor CLI agent across all clouds (#3018)

* feat: add Cursor CLI agent across all clouds

Adds Cursor's terminal-based AI coding agent (the `agent` command from
cursor.com/cli) to the spawn matrix. Routes LLM requests through
OpenRouter via --endpoint flag and CURSOR_API_KEY env var.

- manifest.json: new cursor agent entry + all 6 cloud matrix entries
- agent-setup.ts: install, configure, launch, and update definitions
- Shell scripts for all 6 clouds (local, hetzner, aws, do, gcp, sprite)
- Config: writes ~/.cursor/cli-config.json with full permissions
- Icon: cursor.png from cursor.com/apple-touch-icon.png
- All cloud READMEs updated with cursor.sh usage
- CLI version bumped to 0.26.0

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

* feat: add spawn skill injection for Cursor CLI

Writes a .cursor/rules/spawn.mdc rule file with alwaysApply: true
during setup, teaching the Cursor agent how to use the spawn CLI
to provision child cloud VMs. Uses the same base64 upload pattern
as other agent config files.

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

---------

Signed-off-by: Ahmed Abushagur <ahmed@abushagur.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: A <258483684+la14-1@users.noreply.github.com>

sh/aws/cursor.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+set -eo pipefail
+
+# Thin shim: ensures bun is available, runs bundled aws.js (local or from GitHub release)
+
+_ensure_bun() {
+    if command -v bun &>/dev/null; then return 0; fi
+    printf '\033[0;36mInstalling bun...\033[0m\n' >&2
+    curl -fsSL --proto '=https' --show-error https://bun.sh/install?version=1.3.9 | bash >/dev/null || { printf '\033[0;31mFailed to install bun\033[0m\n' >&2; exit 1; }
+    export PATH="$HOME/.bun/bin:$PATH"
+    command -v bun &>/dev/null || { printf '\033[0;31mbun not found after install\033[0m\n' >&2; exit 1; }
+}
+
+_ensure_bun
+
+# SPAWN_CLI_DIR override — force local source (used by e2e tests)
+if [[ -n "${SPAWN_CLI_DIR:-}" && -f "$SPAWN_CLI_DIR/packages/cli/src/aws/main.ts" ]]; then
+    exec bun run "$SPAWN_CLI_DIR/packages/cli/src/aws/main.ts" cursor "$@"
+fi
+
+# Remote — download and run compiled TypeScript bundle
+AWS_JS=$(mktemp)
+trap 'rm -f "$AWS_JS"' EXIT
+curl -fsSL --proto '=https' "https://github.com/OpenRouterTeam/spawn/releases/download/aws-latest/aws.js" -o "$AWS_JS" \
+    || { printf '\033[0;31mFailed to download aws.js\033[0m\n' >&2; exit 1; }
+exec bun run "$AWS_JS" cursor "$@"