Fix deploy job: remove sudo from non-interactive SSH commands

[Copilot]

The deploy job was failing because sudo in a non-interactive SSH session has no TTY to read a password from, causing an immediate exit.

Changes

• .github/workflows/portfolio-ci-cd.yml: Replace sudo mkdir -p ... && sudo chown ... with a plain mkdir -p in the "Sync files to server" step

# Before
ssh -p "$TARGET_PORT" "$DEPLOY_USER@$TARGET_HOST" \
  "sudo mkdir -p '$DEPLOY_PATH' && sudo chown '$DEPLOY_USER':'$DEPLOY_USER' '$DEPLOY_PATH'"

# After
ssh -p "$TARGET_PORT" "$DEPLOY_USER@$TARGET_HOST" \
  "mkdir -p '$DEPLOY_PATH'"

mkdir -p is a no-op when the directory already exists, so this is safe for all subsequent deploys. Initial server setup requires a one-time admin step to create $DEPLOY_PATH and assign ownership to DEPLOY_USER.