fix: Schema alignment and code corrections (COA 2)

- Replace owner_id → owner_user_id in all queries
- Replace auth_token → companion_agent_token in server_connections
- Replace l.active → (l.status = 'active') checks using ENUM
- Fix AppError → ApiError in all new API files
- Add missing imports (Path, PanelAdapter trait)
- Fix StoreConfig nullable type mismatches

Resolves 122 compilation errors. Only sqlx cache generation remains.

Phase 3: EXECUTE complete per V4_WORKFLOW

generate-sqlx-cache.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+set -e
+
+echo "=== GENERATING SQLX QUERY CACHE ==="
+echo ""
+
+# Install sqlx-cli if not present
+if ! command -v cargo-sqlx &> /dev/null; then
+    echo "Installing sqlx-cli..."
+    cargo install sqlx-cli --no-default-features --features postgres
+fi
+
+# Set DATABASE_URL to local postgres container
+export DATABASE_URL="postgres://corrosion:${DB_PASSWORD:-corrosion_dev}@localhost:5432/corrosion"
+
+echo "Testing database connection..."
+if ! psql "$DATABASE_URL" -c "SELECT 1" > /dev/null 2>&1; then
+    echo "❌ Cannot connect to database. Make sure PostgreSQL container is running."
+    echo "   Run: docker ps | grep corrosion-db"
+    exit 1
+fi
+
+echo "✅ Database connection successful"
+echo ""
+
+cd ~/corrosion-admin-panel/backend
+
+echo "Generating sqlx query cache..."
+cargo sqlx prepare --workspace
+
+echo ""
+echo "✅ Query cache generated in .sqlx/ directory"
+echo ""
+echo "Now commit and push the cache:"
+echo "  git add .sqlx/"
+echo "  git commit -m 'chore: Add sqlx offline query cache'"
+echo "  git push"
+echo ""