fix(install): recreate local install script and source fallback launcher

Co-authored-by: Codex <noreply@openai.com>

install.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+log() {
+  echo "==> $*"
+}
+
+fail() {
+  echo "ERROR: $*" >&2
+  exit 1
+}
+
+need() {
+  if ! command -v "$1" >/dev/null 2>&1; then
+    fail "required tool not found: $1"
+  fi
+}
+
+need node
+need npm
+
+cd "$ROOT_DIR"
+
+if [[ "${CO_MONO_SKIP_INSTALL:-0}" != "1" ]]; then
+  log "Installing workspace dependencies"
+  npm install
+fi
+
+if [[ "${CO_MONO_SKIP_BUILD:-0}" != "1" ]]; then
+  log "Building core packages"
+  BUILD_FAILED=0
+  for pkg in packages/agent packages/ai packages/tui packages/coding-agent; do
+    if ! npm run build --workspace "$pkg"; then
+      BUILD_FAILED=1
+      echo "WARN: build failed for $pkg; falling back to source launch mode."
+    fi
+  done
+else
+  BUILD_FAILED=1
+fi
+
+if [[ "$BUILD_FAILED" == "1" ]] && [[ ! -f "$ROOT_DIR/packages/coding-agent/src/cli.ts" ]]; then
+  fail "No usable coding-agent CLI source found for source launch fallback."
+fi
+
+LAUNCHER="$ROOT_DIR/co-mono"
+cat > "$LAUNCHER" <<'EOF'
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+if [[ -x "$ROOT_DIR/packages/coding-agent/dist/pi" ]]; then
+  exec "$ROOT_DIR/packages/coding-agent/dist/pi" "$@"
+fi
+
+if [[ -f "$ROOT_DIR/packages/coding-agent/dist/cli.js" ]]; then
+  exec node "$ROOT_DIR/packages/coding-agent/dist/cli.js" "$@"
+fi
+
+if [[ -x "$ROOT_DIR/node_modules/.bin/tsx" ]] && [[ -f "$ROOT_DIR/packages/coding-agent/src/cli.ts" ]]; then
+  exec "$ROOT_DIR/node_modules/.bin/tsx" "$ROOT_DIR/packages/coding-agent/src/cli.ts" "$@"
+fi
+
+echo "ERROR: no runnable co-mono binary found and tsx fallback is unavailable." >&2
+exit 1
+EOF
+
+chmod +x "$LAUNCHER"
+log "Created launcher: $LAUNCHER"
+log "Run with: ./co-mono"