chore: update dev script and add ADB download helper

dev.sh now runs preflight checks (build backend, build desktop,
wails generate module, npm install + tsc) before starting wails dev,
so type errors and binding mismatches surface immediately. Adds
download-adb.sh for fetching platform ADB binaries to embed in
distribution builds.

scripts/dev.sh

@@ -2,20 +2,35 @@
 set -e
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
-
-echo "[DroidScope] Starting dev environment..."
-
-cd "$ROOT/frontend-react"
-npm run dev &
-FRONTEND_PID=$!
-
-cd "$ROOT/desktop"
 export PATH="$PATH:$(go env GOPATH)/bin"
-wails dev &
-WAILS_PID=$!
 
-echo "[DroidScope] Frontend PID: $FRONTEND_PID"
-echo "[DroidScope] Wails PID:    $WAILS_PID"
+# ── 1. Build backend-go ────────────────────────────────────────────────────────
+echo "[1/4] Building backend-go..."
+cd "$ROOT/backend-go"
+go build ./...
+echo "      ✓ backend-go"
 
-trap "kill $FRONTEND_PID $WAILS_PID 2>/dev/null; exit 0" INT TERM
-wait
+# ── 2. Build desktop (Go) ──────────────────────────────────────────────────────
+echo "[2/4] Building desktop..."
+cd "$ROOT/desktop"
+go build ./...
+echo "      ✓ desktop"
+
+# ── 3. Regenerate Wails JS bindings ───────────────────────────────────────────
+echo "[3/4] Regenerating Wails bindings..."
+cd "$ROOT/desktop"
+wails generate module
+echo "      ✓ wailsjs"
+
+# ── 4. Install & type-check frontend ──────────────────────────────────────────
+echo "[4/4] Checking frontend..."
+cd "$ROOT/frontend-react"
+npm install --silent
+npx tsc -b --noEmit
+echo "      ✓ frontend"
+
+# ── Start dev ─────────────────────────────────────────────────────────────────
+echo ""
+echo "Starting Wails dev server..."
+cd "$ROOT/desktop"
+wails dev